The Revo is a decent first time buy. And if you decide you want 2wd, you could always disconnect the center shaft going to the front diff. But, I can almost guarantee that you'll prefer 4WD.
BTW: Unless you can lock the center diff in just about all buggies/truggies (1/8th scale trucks), you can't do the 2wd mod easily.
Revo 3.3 is an excellent option. I have one and love it.
An E-Maxx would be ideal if you prefer electric. The emaxx got me hooked on monster truck and started me on the path to owning (1) T-Maxx w/mild mods, (1) e-maxx w/mild mods, (1) Seriously modded Brushless Supermaxx/E-Maxx, (1) Revo3.3 w/mild mods, and now my Brushless CRT "Truggy".