i need to know:
17x7 +34 ... all 4 will be the same size/width/everything.
running that on a xB.
how will that fit? will it be low enuff offset?
keeping in mind the width of the rim is still just 7(not 8 or 7.5)

 

It will look good but you still could go lower. Im building hubcentric spacers in various thicknesses for myself to play around with so if you need any, let me know

IMO, i would slap a 5mm spacer up front and 10mm in the rear in your situation.