Whew, thinking about this makes me tired!! I'm sure a side window can be installed to look neat but......
I owned a 52 Panel for years and for the same reason wished I had a suburban . Although I did not do it the guys who I would enlist to help always told me to sell it and go find a suburban! When I restored my panel I actually "fixed" someones attempt to put a side window in it. I'm sure what you want to do can be done but perhaps there is a suburban just around the corner waiting on you?? I have read where some of the trim may be hard to find if you wanted to make it like a suburban??
I'm sure some Burb owners will be of a lot more help so just stay tuned.