Adding a Rad to your collection is a great idea...I cannot get enough of my 232 that I picked up recently. For strap sizing, it all depends on the look you want. I find that the 26/26 straps with a nice sewn in flat buckle will give the Rad a more historic/vintage look. If you want to dress it up...a 27/22 gator will do the trick nicely.
So far, my favorite is the OEM 26/26 JV gator strap. The 26/26 width is nice and meaty looking, but the sueded gator is still refined.
I also got a 27/26 vintage leather strap, and I think that is my favorite size option so far.
I just shot a bunch of different strap combos on the 232, I'll post a couple of them once I get them edited.