Help deciding between Mini and iMac

I am going off to college next month and I am trying to decide on a desktop mac for myself. I currently have a Macbook, which I am very happy with, however I need a desktop as well for backup purposes, and if my macbook ever crashes.

My decision is between a Mini and an iMac.

I have used a mini in the past, and have been happy with it. My main question is will I notice much of a performance difference between a 20" iMac Intel and a Core Duo Mini with a 20" or 24" Dell monitor?

I would like to get a Mini and a 20" Dell simply becuase it is much less money. I can get the mini and the 20" for about 1000, and with a 24" for about 1400. I will mainly be using firefox, itunes, iphoto. Once in a while I will use Photoshop and garageband, but not more than once a month. I know that ram is the most important, I have 2gb in my macbook, and have and extra 1gb chip for whichever one I get.

I do not want to spend the money on a powermac, as it is way past my needs.

Thanks for all the help.

Assuming that your dorming, I would recommend you bring just the Macbook. If your worried about backing up data, get an external HD and backup software like Roxio's Deja Vu, or keep the external HD formated FAT32 and you'll be able to access it on a windows PC if need be. Plus buy an extended applecare warranty to cover your system longer and you'll be set.

I would recommend you getting the iMac. Because if you buy a Apple display it almost equals out to an iMac. So preferably get the iMac 20 or 17 inch whichever one you prefer. iMac is my choice.

iMac has a real video card (ATI 1600). Mac Mini has some crappy "mobo vid card" as I call it, Intel 64mb card.

You can't upgrade the mini's vid card, if you ever plan to play any serious games one day, the iMac will be worth the money. Plus you'll have better HD access (7200RPM instead of 5200) without resorting to external.

These are my only gripes with mac minis. I own one, and I love it.

Figured I'd let you know the bads and decide if it helps you determine what you want.

I say you get an external hard drive, it's a heck of a lot cheaper (you can get about 500 GBs of storage for less than a mini) and is fail-safe.