Long story short - I built a HTPC with a Phenom II, and possibly skimped on the case - namely a $40 "slim" Micro-ATX case with an included Flex 300W ATX12V PSU. After finding out about the Dolphin Wii emulator, I've added a low profile Radeon 6670 card, in addition to a TV tuner. Furthermore, I want to overclock the CPU and possibly unlock the 3rd core (which I verified works before adding a lot of the additional expansion cards), but I fear this will destroy the crappy power supply. Does anyone know the best means to acquire a reliable replacement power supply of this form factor (Flex ATX12V)? My internet searches bring up random PSU's from non-standard internet sellers, with little or no feedback about the products.
Or am I just better off buying a more expensive new case that can accommodate a standard PSU?
Get the new case. Newegg has had the antec 300 with 430 or 500w antec ps on sale for around $70 recently; stick with antec, corsair, ocz or seasonic power supplies. Some of the other brands are junk. You can go cheap on the case brand, but not the ps.
What is the make and model of your Micro-ATX case?
What is the make and model of the existing power supply unit?
For a system using a single Radeon HD 6670 graphics card AMD specifies a minimum of a 400 Watt or greater power supply. The power supply should also have a combined +12 Volt continuous current rating of 22 Amps or greater.
Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Total Continuous Amperage Available on the +12V Rail(s) is the most important.
Try to find a power supply that has a +12 Volt continuous current rating of 22 Amps or greater.
Flex ATX Form Factor power supplies are a general class of small form factor power supplies that include Micro ATX, SFX, TFX, etc. form factors. When you say you have Flex 300W ATX12V PSU it really doesn't tell us much, other than its smaller than a standard ATX form factor power supply.