0 offset

im bout to order some 15x8 wheels and would like to know how well they fit. though thats a broad based question, i am wanting 0 offest in rear and maybe a 15x7.5 up front but with a negative offset so the lip is equal on both. im worried i will rub suspensiopn though. i guess i want to know the limits on how far in i can go before i hit inner fender. 
