Interesting. A C2D LGA-775 board made for DDR3.
You're best to review the QVL list; see what manufactures are recorded; possibly -- extrapolate your findings there to an available kit.
Or -- order the Samsungs, test and take your chances. Hopefully, the reseller has a return-policy on the purchase.
UPDATE: The QVL list contains a 4GB Samsung model M378B5273BH1-CF8, and there's a Transcend module using a Samsung part number.
A good chunk of the QVL list includes 1 and 2GB modules rated at 1866 to 2200 Mhz, annotated with "downgrade to 1066." That means you would buy such modules and then run them at the lower speed, I think.
Generally, a QVL list is only a sample of makes and specs tested for the board, and you can extrapolate or "guess" that similar modules by those manufacturers would work.
The Samsung model I listed is the only 4GB module in the QVL list.
I'm just making a shot in the dark here that the modules the OP found at EBay are very likely a fit for this board.
Anybody else have an opinion?