Check out my post in this forum called "My Fiesta ZT". I am running 7.5" x 16" (Not sure on the offset but I can check if needs be) with 205/40 16 tyres on, lowered 40mm - I had the arches 'trimmed' they don't rub and look awesome.

What you can put on all depends if you want to do any arch work or not mate.

If you can afford them get some yoko parada's they are awesome tyres - very very sticky and they look cool too