This may not be the best idea if you're new to the whole thing, but an interesting approach using something like MythTV would be to have a single, large, powerful, expensive, noisy server churning away somewhere out of sight and mind. You can then build and configure as many front ends as you like, all that use the same backend and therefore have the same resources.
This means your front ends can be:
a) linked together with the minimum of hassle
...in my mind that's the approach to take these days, especially if you'll be wanting more than one around the house. Might not suit your needs, but I thought I'd throw the idea out there in case