Sorry to burst your bubble, Trotter, but I know for a fact that normal-size ATX power supplies will definitely fit into JFish's case. JFish has what we normally call a "Mini ATX Tower." Although his case is only large enough to support MicroATX motherboards, the screwholes and space in his case support regular-size ATX power supplies.
The only time one would need a true MicroATX power supply is if one had a slim MicroATX case, such as an Antec Minuet II. These power supplies are substantially smaller in size. They typically only feature 60mm fans instead of the standard 80mm or even 120mm fans used in standard ATX power supplies. Slim MicroATX cases such as these also only support half-height expansion cards, which is definitely not the case in JFish's system since it uses a full-height PCI card.
I would recommend looking more closely at a system's specification before jumping to conclusion next time. The power supply that JFish ordered will most definitely fit into his system. In fact, if he were to order any of the supplies you gave links to, those would NOT work in his system - they would not even screw in properly!
Just so you know, JFish, your power supply will work perfectly in your system. A more sensible upgrade than replacing your motherboard might be to purchase a set of high-CFM fans that would allow your system to run not only quieter, but also cooler. Your system can run up to a 92mm fan in the rear, so look into getting a nice Panaflo fan for the rear of your system.