Just an idea, building up on Trotter's suggestion of getting a discrete graphics card with passive cooling (only heatsink, no fan), instead of that case and PSU you could go for something like an Antec Sonata, which comes with a very good and relatively quiet PSU. While being far from the best Antec case, both the case and the PSU crush the Rosewill in your spec, and your dad will be very thankful for a much
more quiet PC.
The Sonata is made to be quiet, so the panels have soundproofing, etc. At 129US$ (with the Antec 500w PSU) it's more expensive, but I think it's a big upgrade for the kind of stuff your dad wants the computer for, and it will knock MANY decibels off. There is also a very good and very quiet 120mm case fan included. That PSU will also provide more headroom for any internal upgrades in the future. In my opinion, it's well worth splashing the extra 60 bucks or so if you can.
Newegg.com - Antec Sonata III 500 Black 0.8mm cold rolled steel ATX Mid Tower Computer Case 500W Power Supply - Computer Cases