Sorry for late response!
Anyways, your motherboard can easily handle that card as it must be having PCI Express x 16 slot with bus interface atleast greater than 1.0 . The card requires a PciE x 16 slot with bus interferance upto 3.0 . So, it is compatible.... Dont worry about the size as it stands on the motherboard on that small PCIE x 16 slot.... Go for that GPU, but remember to have a big case with eligible PSU.