Re: Help me with this trade...
If it's the plain speed you're after, I don't think you need to make the trade. The guys you have should be fine in that regard. BP and Rollins are good for 20-30 a piece, maybe more for Rollins. And all things I've heard on Taveras have him aiming to swipe around 50 in Colorado.
An ace and a good closer, which are hard to come by, is a steep price to pay.