Rule #1 of pc repair and building. Never cheap out on a power supply. Ever. The DX 4300 will accept any PS2 compatble power supply, this list (http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html) Will tell you what brand is the best. According to NVIDIA, the GTX 950 only requires a 350w PSU. You can usually find a good PSU of that wattage for about $30 USD. You should probably look at tier 2 and/or 3. They will have the best pricing.