I have two gts 250s so that means that I will use both of the 6 pin connectors as well as 4 molex with the two molex to 6-pin adapters. The optical drive and the hard drive will each take one sata connection, right? The 24, 4, 8 pins go to the motherboard and so all that leaves me is 2x molex connectors, 1x 8-pin, 1x sata.
I want to use 5 case fans and I have this motherboard...
Ultra does not have a reputation for high quality power supplies. Having only 45 amps on the +12 volt rails is a sure sign they are cutting corners. Having only two, 75 watt, 6 pin, PCI Express power connectors is another sure sign. The specifications look like those for a typical 500 watt power supply. That particular 750 power supply is made by Wintech Electronics for Ultra. Wintech is known for low budget, low quality power supplies of questionable performance and value.
The Corsair TX750 is a high quality power supply that can deliver the power for a full load even at high temperatures. It has a single large +12 volt rail rated at 60 amps, and the required number of 75 watt, 6 pin, PCI Express power connectors. It has consistently earned high marks in technical reviews. It is stable, reliable, and comes with a five year warranty. Here is a link to one of many technical reviews of that psu: