Here's what I found:
Computer IBuypower I-Series 301 - If this is not your computer then you will need to take a ruler or tape measure and measure from the rear of the case to the rear of the drive bay (or hard drive). That is the space you have for the graphics card. As long as the card's width is less than that space, it will fit in your case.
Again if the computer above is yours, it looks to have a standard ATX power supply and the only you chose should fit in there without issue.