ITX server build Looking for mobo recommendations for Socket 775/AM3

I want to upgrade an old WHS2011 system I have. The hardware is over 5 years old and thought it was probably time. I have a fractal design Node 304 for the case.
The server will be used to back up computers and make TV shows, movies, and music available to HTPC, Roku, and a few other mobile devices. I'm not sure how much CPU will be needed but have a E2180, Q9550, and a unlockable Phenom II 550. I'd like to use one of these but will get a new CPU if needed.
I'll need 6 sata connecters on the board and I'm not sure if there are very many out there that have that many and will work with these CPUs. Would there be any drawbacks to using a PCI card to add more sata connections?
Would the E2180 or Phenom II 550 be good enough to transcode 2+ steams at a time? Should I just move to a current motherboard and cpu combo? If so, what CPU would be a good low cost, low power choice that will be enough to transcode. Thanks

Move to a new combo if you need itx. Otherwise find a p35/45 or x38/48 motherboard on ebay or craigslist

That's the problem... no new boards for socket 775. Also, socket AM3 and ITX doesn't go well together.

Six SATA ports is also a rarity with ITX. ASRock makes some FM2/FM2+ boards using the 85X/88X chipsets with 7 or 6 SATA ports. ASRock and Asus makes some socket 1150 boards with 6 SATA ports. That's all I see on Newegg right now. IIRC Asus made a socket 1155 H67 board with 6 SATA ports, but it may no longer be available.

I know it probably wasn't the best idea, but I was going to look for a used board if I could find one that had that would work. I don't think there are very many out there that has the number of sata that I need. What are the drawbacks of going with an add on card instead?
I'll probably just go with a new board/cpu combo. Even then there are not a lot of options with enough sata connections. Do most people just use an additional card to get extra sata connections?