I like your ride. Great to hear your 302 is running smooth to thats always a bonus. Iam a fan of the blue as well it looks nice. Nice tires to! A little rust on the floor pans is common and is pretty easy to fix if it isn't rusted right through to bad. I suggest checking out the frame rails, toe-kicks, and cowl for sure just to make sure you don't have leaks! If it is in good shape you can probably get away with patching it and then giving it a good rust inhibitor.
I took apart the doors the other day and gathered up all the material I need to take out the old 289 and 4 speed tranny. Probably get that out right away and put it on the stand once I get the proper bolts. I would suggest going at least disk breaks on the front for sure.
Right now iam fighting all the hidden rust I keep finding and iam leaning towards sand blasting my ride to find the real trouble spots before I start dumping cash into my rust bucket!