Wheel and tire help..

OK guys, I am getting ready to buy some FR500’s with new tires.I need some help with picking the rim and tire size. I am going to go with 17’s, I know that. I also know I I think that I want to put 245-45-17’s up front on a 17x9 rim but my problem is what should I put on the back. What will fit under a 93 Lx. I have the 5 lug converson and the car is lowered about 2.5 in front and about 2 in the back. What is the best setup for me to put on the back of the car? Will the 245-45-17’s look ok with the 40’s on the back? What will fit the best?

Front
245-4517’s on a 17x9

and in back:

255-40-17 on a 9 inch rim
or
275-40-17 on a 9 in rim

I am going for a look like this:
http://picasaweb.google.com/skipnutz/Mustang/photo#5083540382159478930

Thanks in advance for you help...