Yup, gotta check both sets of lugs! Do that and you'll be fine.
Problem will be finding 15" wheels with enough backspace. Most of the off the shelf 15" wheels barely have enough backspace as it is, finding them with an extra 1" will be hard. For example, normally a 15x7 with 4.25" of backspace fits great on the front. To get the same fit, you'd need 5.25" of backspace. But finding 15"x7" wheels with even 5" of backspace is a tall order, normally requires custom.
Not saying it's impossible or anything, but if you're looking for 15" wheels it will be tough. If you want 17" or 18" wheels, much easier.
