Nice question, rioh. I would definitely take that deal. Sizemore is a Top 5 player, and Garza and Damon are expendable as a result.
Any hey- just FYI... if you're like me and always hungry for fantasy input, you may want to start posting your trade questions on both Yahoo and http://rotomania.com. I don't know if you've ever been there before, but the cool thing about Rotomania is that every time you ask a fantasy question, your entire roster and league settings are automatically displayed so that people can give you more informed advice.
Plus, you get notified via email whenever someone replies to your post. I hate having to wait around refreshing the page to see if anyone responds.
Anyway- you should check it out. Here's a trade involving Sizemore that I just saw on there: