I really don't see why KG wouldn't be successful in that era - likewise Paul Pierce.
Both of those guys are warriors who play HARD every single night. Not afraid to talk trash, not afraid to take a hit and get right back up, not afraid to play through pain.
Kevin Garnett (even at his peak) could probably never play center in that era, but as a PF he would be elite. The only guys I see giving him some trouble would have been Malone and Barkley becuase of their pure bulk-strength, but KG is deceptively strong.
KG is an ultra talented guy who plays ever asppect of the game well - he's a top tier defender, rebounder, passer and scorer (at least at his peak).
Paul Pierce especially would have fit that era. He is toughness personified, and at 6'7" 230lbs he was have absolutely had the muscle and size to bang with any SF from Jordan's era. Hell he still muscles up with guys like MWP, Lebron and Carmello on a nighly basis.
Rondo, ironically, also would have done very well. Stockton was never big physically, but he was tought - he never took garbage from anyone, he'd play hurt and he was generally a warrior. Rondo is a very similar player, and his ability to play hurt would have served him very well back then.
Next is Steve Nash. Again a guy who is tough, plays through injuries. He's not big, but he's a guy that doesn't depend entirely on his slashing - he's one of the best shooters and passers of the last decade. If Stockton could be a great player in that time, so could Nash.
Carmello is another. He's 6'8" and about 230-240 pounds. He's big enough that he can take a beating physically, but he's a multi-dimensional scorer and a very good rebounder who could have very easilly done well in an era that saw guys like Glen Rice and Steve Smith be successful.
Ray Allen can do anything that Reggie Miller could do in his time - at his peak he easilly could have been a dominant player in Jordan's era.
Al Jefferson isn't very good defensively, but he's big and he's pretty tough with a good low post game. He wouldn't have worked as a center, but as a PF he would have done well against guys like Karl Malone.
Kendrick Perkins (and many other role players like him) would have fit in just as well back then. Is Jordan going to tell me that Perkins couldn't have been just as successful on his Bulls team as Bill Cartright, Luke Longley or Bill Wellington?
How about somebody like MWP or Gerald Wallace - guys who have very defensive games to Dennis Rodman (based on stregth, toughness and atheticism).
Personally I think Dwyane Wade would have been equally dominant. He's a very similar player to Jordan in that he's more of a slash who's not really so well known for a great Jumpshot (Jordan was never THAT good an outside shooter). Wade is pretty strong and bulky for a guard dispite his size, he's always been a very good defender and his combination of strength and athleticism has always made him difficult to match up with. You can't question his size, because Joe Dumars was no bigger.
Personally I don't really know that Duncan would have fit so much, becuase as much as he has the size and the talent, I'm not sure if he'd have the mental toughness to deal with the physical nature of the league back then. I always have (and still do) see Duncan as more of a finesse big and too much of a 'nice guy', and I think he would have been beat up on a nightly basis playing regularly in those days.
I also think Lebron might struggle, because he doesn't deal well with physical basketball and wouldn't get all of the rediculous calls he gets now days. He'd still be very good, but I don't think he'd be as dominant as he is now, because he'd be knocked on his backside every time he tries to take it to the basket.