Are Coolmasters PSU's any good

Oh, I almost forgot...

The coolmaster only has a 20 pin main connector. This may be what you are looking for, but most newer motherboards use the 2.0 spec 24 pin connectors.
 
The Cooler Master power supply is a re-branded HiPro. HiPro makes some pretty cheap stuff, but then, I haven't had one blow a system apart when it failed, such as even cheaper brands often do.
 
Check my link (above) to Microdirect.com. This is a high-value no-bling solid choice. It is not a "brand name" per se. It is the cheapest PSU that I would buy. Even at UK prices it's not a lot of money.
 
If your AMD (or Intel for that matter) board uses a 20 pin main power connection, then you need about 20mm of empty space for the 24 pin to work. 4 pins will remain unused. You can also get a 24 pin to 20 pin adapter (and the PSU may come with one). Usually the adapters come with motherboards though.