17's and 15's

Typically if you stagger diameters it goes the other way, because the taller rear tire tends to make the rim itself look smaller. So you run larger diameter wheel in the back with a taller tire and keep the sidewall height similar front to rear. The sidewall height being the same makes the rims look the same size, even though they aren't.

So, for cosmetic purposes you might want to see if there's anything for an 18" rim that would suit your tire purposes. There's a lot more tire selection in 18" than there is in 17".

Now, if this is strictly a drag racing set up then carry on, you'll probably find what you need in a 15" rim. Personally I'd be looking at how much drag racing you do, and if it's worth just have a set of rims/tires for the strip.