Mac mini good enough for constant streaming?

Hey all, Im getting an apartment next month and want to get a mac mini to use as an htpc. If I am going to stream a lot of videos, should I upgrade the RAM right away? Is this going to be the main reason if the streaming is choppy? Is the onboard graphics card of the Mini good enough? My tv is 1920x1080. Also what would be a safe cable speed to use? I have 3 computers running at most. Will be gaming, downloading movies and streaming. Any other suggestions would be nice, and some good sites for streaming video. Thanks

I have a Mac mini. I own the $799 model with the 2.53GHz Cord 2 Duo processor, 4GB of RAM and a 320GB hard drive.

You will not have any issues streaming video content to the mini. It is a very capable machine and will serve you well as an HTPC. Although the base model should serve your needs well enough, I suggest spending the extra money for the $799 model if you want to upgrade the RAM. You'll likely have to spend an extra $100 for RAM anyway if you buy from Apple, and for another $100, you can also get a hard drive that is twice as big and a faster processor (which is itself a $150 upgrade from the base model's 2.26GHz CPU).