mac people: iMac as entertainment server?

[jeffdrafttech]

I am thinking about getting a desktop PC for home that will be used primarily as an entertainment machine.

The iMac has a mini-DVI output port according to the site. Has anyone used one of these with a decent television display with good results? Also, what kind of extension can be used with that mini DVI port? Apple doesnt list a long mini-dvi cable. Is it just a 1/8in headphone-type connection? Would a well shielded 1/8 headphone extension cable work, in combination with the mini-dvi to DVi adapter apple sells? I have a ceiling mounted 480p cinema projector that does a great job but is about 20-25ft from where I would have the computer setup. I like the higher resolution television shows in the itunes store and would love to set up a way to pipe them to my projector.

Also, Apple lists a USB terrestrial-HDTV tuner for $250. Anyone used this? Does it work well? Does the MAc machine work well as a DVR with it?

I considered the mac mini because I could just ceiling-mount it beside the projector, but I like the idea of having a more powerful machine with a built in display. The hard drives in the minis are pretty small for collecting TV show downloads.

Also, if you know anything about them, how do they compare with Windows Media Center PCs?