First I must say the car looks great! Those are my two favorite colors!!
The wheels will fit fine, the front is the 'works all the time' sizeing and the rear will work out to be the same as the 9.5" w/ 5.5" b.s (works all the time size).
The tire choice is limiting you a bit as they don't offer all the normal sizes. Your front choice is a little short for the car, I would like to see it be at least 25.5" tall (245/45/17), especially if you aren't really lowering it a lot. BFG's 245/40/18 @ 25.7" would be ideal. If you went with a 245/45/17 tire it would match very closely to your proposed rear tire sidewall size...I think if you go larger diam. on the rear wheel it still looks best to match the sidewall heights, this makes the whole package appear well thought out.
The rear tires are taller but I know you have some fender well to fill and I'm all for it. My car (68 camaro)
is quite low so this isn't as much of an issue for me. I think you are on the right track here! Just set your final ride height the best you can so you can really nail the tire fitment!!
If it were me and I was really wanting that BFG tire I would get the 225/45/18 and the 255/45/18. This would give you a very close sidewall height between the two (rear sidewall .25" taller) and more importantly the sidewall to rim would be stretched the same on both wheel widths...I think they would look great on your chosen wheels. This of course isn't the widest package you could run, but it should fill everything up nicely (as long as you have lowered it a little) and not have any rubbing issues!!
Again, I would measure what you need in the rear height wise as you can get that tire in quite a few heights....
Hope this helps!! BTW, Like Jason, I too have done this before...