the suspension difference isnt in the geometery but the springs and shock rates instead.. your mothers maxima rims will fit fine..... I'd look at getting 17x7 since its a common size and available widespread at a good price..

The reason the 7.5's are a different offset is partially because of their extra width. I dont know the specs on the 2000max but if u used www.tirerack.com to order or www.discounttiredirect.com i can pretty much guarantee they will fit.. IF you order tires at the same time, they can come mounted on the rim already and then you just throw them on at home and your good to go..