the 04's were the first ones with limited slips, i would at least go for one of those...
its a tricky thing though, because srt4's are the DSM's of today. So many people bought them cause they were cheap and quick, then they beat the hell out of them, modified them like an amature, and sold them after they were hacked up.
Ive worked on many, but few people whos srts i worked on ever did wise and tasteful mods...buy an all stock srt4 and you should do alright...