Jim:
Here are a few suggestions to consider:
First, I really like your idea of taking several months to make, and savor the trip. The US of A is a huge piece of real estate. Zipping across the country in a couple of days, a week, or even a month doesn't seem likely to satisfy a good itch to travel. I hope to make a similar tour of our native land in the relatively near future.
IMHO, western flying in the lower 48 is a bit different from AK, and certainly different from flying east of the Mississippi. Density Altitude is a bitch that WILL bite the unlucky and unwary. I hope you will find a way to get some mountain flying training. Several outfits do a really good job of it. Most of the places that do mountain flying instruction I know of want pilots to fly behind at least 180 HP. Lori McNichols at McCall, ID has good credentials. I've heard her speak at the Northwest Aviation Conference held each year in Puyallup, WA and have heard good reviews from some of her former students. The Colorado Pilots Association also has a well regarded mountain flying course. I think you can find them (and others) with any internet search engine. A little time and a little treasure invested in visiting the mountainous western states, spending time with a knowledgeable CFI, and renting a plane to learn new skills would be money very well spent. How are your spot landing skills? How well do you do crosswind takeoffs and landings? How about your emergency skills? How are your flight planning skills? Can you read mountain weather?
Airplanes are machines. Sometimes it's necessary to make field repairs sufficient to get (safely) to an airport with an A&P. When we fly around the country we'll likely be away from easy access to a mechanic anyplace we land in the back country, and even at lotsa smaller municipal airports. For that reason I don't like to skimp on maintenance. if we can start out with everything in A-1 shape we're more likely to make the trip without a hitch than if we depart with any known discrepancies. IMHO, a good rule of thumb is never fly with a known deficiency!
IMHO, a Champ is a bit underpowered for flying in the mountains. Fun to fly, but not well suited for high DA or below gross takeoff weight ops. It's amazing how much junk we carry (emergency tool box, sleeping bag, survival supplies, water, change of clothing, etc.) and how the weight adds up!
Also, while it's legal to fly without a radio or with a 121.5 ELT doing either may not be the best decision. IMHO, a 406 ELT plus some kind of handheld Personal Locator Beacon (PLB) are essential equipment for flying in the west. So is a good panel mount radio. And of course, I carry a cell phone. There be vast distances out west, some with life threatening challenges for those unlucky enough to experience even a survivable/no injury off airport landing. Water, shelter, signaling equipment are a must. The rule of 3's applies: 3 minutes of bleeding, 3 minutes without air, 3 hours without shelter, 3 days without water, 30 days without food. I fly prepared to meet all of these essential needs. I also dress for the crash (which I hope will not happen!) rather than the airport I intend for my destination.
I file a flight plan. Our odds of surviving an off airport emergency landing (aka "crash") go up dramatically if someone comes looking. I plan my flight, file my plan, then FLY my plan. If I don't file, if I depend on a 121.5 ELT or my cell or whatever I could easily spend my short remaining time on earth hoping someone will find and rescue me (and my passenger).
Flying low and slow is great fun. I love the rush, but don't do it anymore. Unfortunately, it just ain't what it used to be. Today we have lotsa wires across rivers, towers on hills, etc. etc. etc. If I don't know the area (intimately!) I avoid flying below 500' AGL. Several pilots get tangled in wires every year. I carry current charts (paper and digital). What if my iPad croaks, overheats & checks out, etc? I suggest if you use digital charts think hard about your backup! Charging the iPad requires power. Lotsa ways exist to meet our need to charge our electronics. Some involve backup batteries, some connect to the aircraft electrical system via a USB port or ??? WIFI isn't always available, sometimes neither is cell service. As you prep for the trip ask yourself whether your ded reckoning and pilotage skills are up to it if you lose your electronic/digital nav tools. Can you read your sectional, then recognize (from above) land forms and terrain so you know where you are at all times?
GPS works great, except when it doesn't. Periodically throughout the year GPS outages occur for various reasons.. I don't plan on landing an any national forests, national parks, public lands managed by the Bureau of Land Management, wildlife refuges, or Tribal lands unless it's at an airport listed in the VFR Chart Supplement (formerly the AF/D). The tickets can be expensive. Notice the little note on the paper chart legend... something about landings on National Parks, National Forests, National Wildlife Refuges, etc. "prohibited". ditto for some DOD and Department of Energy lands. Off airport landings are also prohibited on most Indian Reservations. Some Tribal police forces have been known to damage aircraft they seize for illegally landing on Tribal Lands.
If you are well prepared you'll have a great time. If not, well you may still have a great time, but then again, "stuff happens". I hope preparing for your adventure will be as fun as actually flying it.
Best to you,
John