In the future I may want to turn this into an HTPC, replacing the video card with an 2600XT or 3850 and possibly adding a Bluray player. But I'm questioning if the Enermax 400w PSU is enough to power this system. Since this is just a spare computer I don't want to spend to much money but if you guys have suggestions on anything please be so kind to share them.
More aboutbuild 400w enough
The Evga website recommends a 400watt PSU with 20amps of +12volts. EVGA 7950GT specs You should be good to go with that Enermax Liberty PSU.
Should be fine, Enermax is a good PSU brand, and the PSU has 30A max +12v load, so that is plenty for a 7950GT system.