If cars respond anything like a bike does.. go suspension first.
I did suspension last on my motorcycle and honestly wish i did that first. When I get my Z, thats the route I'll go first. Coilovers, Sways, Arms, etc. Once I thats done, then maybe look at performance stuff like the bolt ons. Although with 5k you can probably do a lot of suspension stuff and bolt ons in one shot so
