recommend me spec for pvr/media pc

Currently record tv using a tv card on my main pc.
As doing this a lot, thought about building a pvr specific pc. Most likely using windows media edition.

Just want some suggestions on suggested spec for one(bearing in mind I will be doing this a fair amount(record 3-4 times per week) so hard drive size prob crucial.

Thinking of using my existing tv card(hauppage pvr350) in the new pc(if this is possible).

I want this pc to be quiet as well as I want to be able to use it as part of my home entertainment sys(and also needs to run cool, location may well be in a cupboard designed for home entertainment and it honestly does not have a huge amount of airflow).

Don't have a fixed budget but want reasonable spec.

btw, do you have to have a separate monitor for windows media edition or do you use your tv for that?