Best motherboard for 720 gaming build

I have a question about which motherboard would be best for an AMD Phenom II 720 gaming build.

Originally I had this motherboard picked out.
GIGABYTE GA-MA770T-UD3P AM3 AMD 770 ATX AMD Motherboard - Retal
http://www.newegg.com/Product/Prod [...] 6813128392

With this graphics card
MSI N260GTX-T2D896-OCv4 GeForce GTX 260 896MB 448-bit DDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail
http://www.newegg.com/Product/Prod [...] 6814127430

I was considering upgrading to this motherboard (once it's in stock)
ECS BLACK SERIES A790GXM-AD3 AM3 AMD 790GX HDMI ATX AMD Motherboard - Retail
http://www.newegg.com/Product/Prod [...] 6813135236

and getting an HD 4870 because it supports crossfire.

Another option I was considering was getting a 750a motherboard so that I could keep the GTX 260 and have SLI.

I'm not partial to either the 260 or the 4870, they both preform about the same, but I would like to have SLI/Crossfire as an option.

Is SLI/Crossfire worth having or would a single cad be better? And then which motherboard would be the best. I'm willing to spend around $140 maximum for the motherboard and both graphics cards cost practically the same.

A little long winded, but it is a difficult decision for me to make.
THX

That one from Gigabyte looks good, but it doesn't support DDR3 RAM. Is DDR3 really an advantage over DDR2 or does it really matter?