|The CaseGears (aka Sunbeam) 480W is NOT good for a modern system. Just look at the specs:|
The high amperage on the +5v rail & minimal amperge on the +12v means that this PSU is suited for P3 & older systems, but not P4 & newer. Old CPUs (prior to the P4) get 100% of their power from the +5v, therefore the amps on the +5v must be high. The +12v on old systems is primarily used by drives & fans only, therefore high amperage isn't required.
The P4 & ALL CPUs since then get 100% of their power from the +12v. Drives & fans still use the +12v, plus video cards are drawing more & more from the +12v. That's why the ATX standard was changed to ATX12V with a multi-rail design for the +12v. The 4-pin ATX12V plug was added as a dedicated +12v source for the CPU. However, the multi-rail design has fallen out of favor lately because it requires "hand balancing" of the components to make sure one +12v rail doesn't become overloaded while another remains unused. To combat this, many manufacturers are adopting the EPS standard (meant for servers) that allows for a single +12v rail with high amperage. It's not unusual to see PSUs with 30, 40, 50, or more amps on the +12v rail these days. With a single +12v rail, component balancing isn't an issue.
You don't have to pay big bucks to get a quality PSU, you just need to know what to look for, plus you should buy from proven reliable manufacturers. I've used this 430W Corsair in several builds without a single problem & it's regularly on sale for just $20. Notice the specs: 80 Plus certified, active PFC, single +12v rail @ 28A, 3 yr warranty:
You mentioned that the CaseGears PSU was for a customer. You actually build/sell/repair computers & would choose a unit such as this one? Yikes! Do NOT use it in place of the Sparkle 300W. Sparkle (aka SPI aka FSP aka Fortron) is a reliable manufacturer, Sunbeam is not.