Bosh isn't any better defensively or on the boards than Amare. And he is less consistent too, has been for his entire career.
And what are those low post moves you are talking about? Can't see them, he is more of a highpost player and a worse shooter than Amare too.
Bosh IS Amare, with less scoring abilities.
This is closer to what I have seen. One on one, amare is a more dangerous, more explosive player, stronger around the rim while bosh is a finesse player with a very good mid range(10-15') game. Their performances are interesting with different matchups. Amare tends to play well against dwight howard, for years. He has also done well against shaq(but maybe not THIS shaq, the one with ju jitsu), and bosh again does not.. Amare has the speed to really bother other bigs while bosh has nice finesse moves that sometimes can be used in the low post(smaller opponents). Bosh does better against smart defenders(that take charges) that may be a little undersized, and does not run the floor on offense or finish at the rim or shoot(15-20') as well as amare. Bosh is a more dedicated help defender than amare, but no better straight up and probably worse. Because Bosh has never won in the playoffs against real competition as the featured player, I dont know if he has ever seen really good defense and done well against it. Amare has been in a funk this year probably due to porters tendency to use him as a jump shooter, and I also think he lost his head. It seems like amare was getting doubled sometimes as soon as he touched the ball and tripled if he drove. He must get the passing game going to overcome all the help defense. I'd be careful about the rebounding as amare has always played with better rebounders on the front line. When you play with bargniani, there are plenty of rebounds available. Playing next to shaq and marion, not so much. I also noticed shaq only had 7 boards in 35 mins last night, but barnes pulled down a ton. Rasheed wallace has only averaged a shade under 7 boards for his career in major minutes(less than amare), but I dont believe he is a poor rebounder, just had some good ones playing along side him.
If I had an offer to trade straight up, yep I'd do it because of amares knees(???) and that bosh probably would be a better complement with shaq, with his better mid range game, and he is a better passer. Add bosh to this team and it would be a 1st round nightmare no one wants to see.