I think the main question is where you are in the standings.
I like Huff for next year if he can ever gain a bit more confidence. He certainly seems to be a big part of the Rays' plans for the future and has a lot of talent, but expectations may be a bit too high. He could be a nice sleeper in '03.
Sandberg is making huge strides. Considering his age, he might actually be a better long-term bet than Huff. He may still be a while away from being a solid fantasy contributor, though.
Mora's value depends almost entirely on his speed. $5 is a nice price, but I don't think I'd make any long-term plans around him. It's far from certain that he'll keep leading off in the future.
If Garland ever improves his control, he could be excellent, but don't count on that happening next year. I'm sure many people will disagree, but I'd like to see him spend more time in the minors.
Broussard could turn out to be a very nice investment - he could become a player in the Jim Thome mold if the Indians show a bit of patience with him.
All in all, this is a solid group of up-and-comers at a sweet price, but none of these players is a sure thing. There are lots of players in the Broussard or Garland mold who never make it in the bigs. If you have a chance to make a push for this year by trading any or all of these guys, I'd do it without looking back. If, in a month or so, you find that your push is going nowhere, trade some of the players you acquired for prospects and take it from there.