Sounds reasonable to me.  
I've got one crt I held on to for lightgun  games, but my space is limited, so it's still in storage.  If I ever hack rgb input into the thing I might bring it back in.  
I'm actually thinking of just picking up a jr. and mod it like you did.... I think the sixers are prettier, but since I'm going to most likely hack it up anyway, I might as well go with the cheapest one.  Heck I might skip the middle man and do a 7800.... I still have all the old 2600 controllers and stuff.