Um, also just come back to 1/10th buggies after a 22 (ish) year break, and to be quite honest, there aren't any *bad* buggies, just cheap ones and expensive ones...... Anything mentioned up there will do it, B44.1, DEX410, FS2, SX3 and so on.
Biggest thing to get your head round will be brushless and LiPo. The basic, cheap, unsensored brushless motor in my RTR 2wd buggy makes the old modified motors look a bit silly. No maintenance, no running in, no "faffing" to get the brushes/comm sorted, it just goes. And it was a bit of an eye opener to say the least!
The 6.5T in the 4wd (Fusion Exceed/DEX410R for what its worth) sends the buggy off like a missile, i've had to turn everything down to keep it controllable indoors. Outdoors is another matter altogether. Get the gearing wrong (or right) and it'll hit speeds that (back in the day) required playing with matched batteries, motors that could only be used for a few runs before a rebuild, smoking speed controllers and so on. Now its just pretty much plug and play.
Decide your budget, see what cars run at your local club (for spares, set up) and go for it. (5.5T will be mental!)