17" tires may be a bit more expensive, but being popular also means more used ones and closeout/ sale type deals might come along. Sounds like you have some fun plans for the bodywork. Are you going to make something clean and nice, or more like a race track beater?
I am all to familiar with one project interfering with another. A few weeks ago I put new brake lines in my truck, put my 8.8 back in, and rebuilt my carburetor. It is really fun and working well judging by the brief test drives I have had it out on, and I was just sorting some minor details to make it completely road worthy, when my pop took his Civic over a curb sideways (fooling around on wet tarmac) a couple weeks ago, bending some rear suspension components and shredding a crossmember. Luckily he was okay, but it took me a week and a half of cutting, hammering, welding, junk yard hunting for parts, and measuring to put it all back together and align it. I do all my work in the street in front of my house, and there is only one spot level enough to safely put a car on jacks. Having to move my truck to another spot and postpone working on it sucked when it was so close to being driveable. I got tired of looking looking at the bottom of that Civic some days, but knowing I could get back to my truck when I was done kept me motivated. When you keep working, you get it all done eventually. At least, that's what I told myself while I was laying on a floor mat in the mud using a door panel to keep some of the rain off me while I pulled a hub and wheel bearing out of a junkyard Civic.