Everyone has their own opinion on tire size with the 3" lift. That's totally up to you, do what you think looks good, regardless of what others say (some will tell you 3" lift and stock tires is ugly, so it's up to you).
Do you know if you have XREAS? Details can be found in the FAQ section if you're not sure how to determine if you have it or not. Any of the spacer lifts will work.
As in the FAQ, Daystar 2.5/1.5, ToyTec 3/2 (they offer us a forum discount btw), and Cornfed 3/2 are all popular options.
Another option if you don't want a full 3" lift is Daystar spacers front/rear. You can get a 2" front spacer and 1.5" rear spacer for under $80 from 4wheelparts.com. Unless you need the extra clearance, this would be a great option if you intend on keeping the stock tires.
That said, I'll say this. Most here, myself included, start out with a small lift only to end up going bigger later on. Many will tell you to get it right the first time, don't cut corners. That's all up to you.
If you've got any questions after this post and reading the FAQ, let us know and we'll help you out in any way we can.