Couple of question on an upgrade

hey, so I recently bought a decent computer off a friend for a good price, I mainly just wanted a new GPU, but he was selling the entire pc for cheap, so i thought i'd see what i could use and sell on anything left over.

So I did take quite a lot of components. but I am slightly concerned about weather my PSU is powerful enough now, I took the 750w ocz he was using.

my new specs are

xfx 6970
EVGA P55 FTW 200
i5 760
OCZ 750w psu
x2 DVD/RW
x3 1TB HDDs
x2 300gb drives
1 60gb SSD
killer 2100 network card.

so is this 750w psu fine to run all this?

I also ran into another problem while upgrading, i have used all 6 of my SATA connections onboard. Would I be able to just get a PCI to internal SATA and it be ok?

help is appreciated.

-Lixah