FWIW here's a photo of my panel. I think it looks pretty good. I've shuffled some instruments / radios around from how it was when I bought the airplane, but otherwise I have to give credit to the former owner(s). I can ignore a funky interior behind me, but a good-looking panel is a must in my book-- as Hammer pointed out, you have to look at it all the time.
As you can see, the radio & txp are down below which I don't mind a bit.
Since this photo was taken, I've relocated the Garmin 196 to the far LH end of the panel and mounted an 8" tablet in the center-stack area.
There are / were a couple issues: the universal joint bolt & nut on the LH yoke shaft just almost touch the back of the DG when the yoke is full aft. If the six-pack had been laid out where the center instruments were slightly to one side or the other of the yoke, that wouldn't be a problem. Another issue was that the airspeed indicator interfered with the LH handhold on top of the panel. The RH end of the handhold was relieved to correct that problem. If the ASI & the turn coordinator had both been mounted a whisker lower, there would have been no interference. But both of these are pretty minor issues.
A u-column is nice but not always required. A friend of mine mounted a radio center-stack in his 54 model. The guy doing the work mocked up a clear plex panel before he laid out where everything went so he could see any points of conflict before he cut any aluminum. There was room for a com radio and a txp above the t-column, and maybe another unit but I can't recall for sure. It was a tight squeak but it fit above the t-column all right. Definitely a radio & txp with a surface mounted GPS or tablet below that should work.
