STI Brembo upgrade help with rim offset

[S13queen]

I recently purchased a front brake upgrade from Z1motorsports which are a set of two STI calipers. I was wondering what the offset for these calipers are because I'm looking into purchasing Rota Grids. I heard that they are +48 offset, but I am not sure. If they are that offset where is the best place should I go to get those rims in that offset??.. no I do not have the 5-lug conversion.