If I was starting out, I'd check the freebie section first. Lots of top quality character morphs there.  Mari_ E17 has a ton of freebie  full character sets for V3 and Aiko, morphs and textures. You can't go wrong with her stuff.

And Vali has 6 top notch ladies free at her site

http://kteam.saiyandesign.com/welcome.htm

And you can stretch your resources a bit, any texture for V3 will work on any morph for her, so you can mix and match.

Purchasing? I would consider characters by  Tivao, Noushka, Vali, and Valea to be the absolute must haves in my runtime. But, as you can see from the other entries, who and what you chose is a truely personal preference. What you could do is go to the V3 section of the store and just browse thru. Something is bound to catch your eye:)