I have heard a lot of good things about the Ruger .44 mag. It's a short "carbine"-style rifle that is proven to be reliable, and with a good, medium-pricedscope will take down whitetails out to 100 yards with good shot placement.
Check out this site http://www.galleryofguns.com/shootingtimes/articles/DisplayArticles.asp?ID=38
I did a quick search and discovered Ruger has come out with a newer version of the .44 carbine.

Good Luck

ps - after reading the entire article, it looks like you'll be spending around $800 for this new versionand a scope. You might want to check out the used guns at your local gun shop or on gunbrokers.com or e-bay if you can't affor that much.