I need CDs to burn Filles over 760 Mb, so I recently bought in T-Com, Pattaya a Pack of 10 CDs ( Smart, blue Color with a Dolphin on it ) ) with 870 Mb - but on my Computer, they show up with only just over 700 Mb !

Can anyone recommend a Brand of CDs, having the real Storage over 760 Mb written on their Label?

First at all: is your burner able to "over-burn" a CD? If so: Has you enabled "over burning"?

Not all Drives and/or software able to "over burn" a CD. That you need to check out to first!