Rims (again)

[barlowe]

I have a 1989 944na and want to put new phone dials on it. The old ones are looking pretty crappy. What are the largest rims (gonna stick with phone dials)I can put on it with no modifications? 16" x 8" on the rear and 16" x 7" on the front? Will I have to go with a lower profile tire if I go up to 16 inch wheels? I don't want to do this.
Also, what are the best size tires to put o my new rims?

Thanks,

Steve

P.S. Wheres the best and cheapest place to get new phone dials?