upper and lower control arms and sub frame connectors are a good start.
Yeah, you should see good gains with lower control arms at a bare minumum. If you can afford it, definitely get a good set of shocks and struts too. I ran the Tokiko Illumna 5 Way Adjustables on my old setup before I had coilovers and they were awesome. If I did it over again, I'd do the same thing. Definitely do subframe connectors too!
PM [email protected] (supporting vendor RE-Performance) He'll give you some awesome deals on the UPR rear suspension. You can also ask him about the shocks and struts.