The fender gap shouldn't be too bad. The 18's and tires are a little taller than stock.
You just started a debate. The word is still out on stock struts with aftermarket springs. I've read some horror stories then I've read some good setups. I'd have to go with a complete shocks and springs upgrade. H&R is a good start. What spring rates are you thinking of going with? That might determine if you are going with stock struts.