318 piston questions

Okay the machine shop just called. :(

My 318 cylinders range from .012 to .015 wear. So they suggest boring the block .030 over and using 8.5:1 flat top pistons. They have the pistons in stock and the boring and pistons will add $320. So should I use their pistons ($140) or should I find my own pistons?

Another question. If we are using 79 model 318 heads (the machine shop took .010 off those to "square" them up) with 8.5:1 pistons will I still have close to 8.5:1 when it is built?

THANKS IN ADVANCE