Honestly do whatever you want. BUt if you want to improve on handling first thing should be hotchkis sway bars and some springs.
Honestly I'm going the total package route I guess. As soon as I get my turbo in I'm going to start saving up for some handling ugprades and go with some sways, struts, and springs or maybe coilovers (not sure yet but I think springs).
Not going to bother with things like rims etc. Celica looks nice stock. I'd rather have some nice surprises under the Hood