The DFI accepts DDR3/DDR3L, not sure about T730. I've got two 8G sticks of DDR3L so that should work.Desktop or laptop SODIMMs? The t730 consumes laptop parts, while the DT122 is on desktop parts. The t730 is designed to be a quiet thin client (shrouded air pathways, a single low RPM fan), while the DT122 is an industrial PC with small diameter, high RPM fans in the chassis. If you have a decent ITX case you could swap the board out, put in some large and slow fans and cut the noise out significantly. Of course, due to a very barebones BIOS setup, you won't be able to take advantage of stuff like HSA or (limited) SRIOV like you can on the t730.
As to the fans, is it the CPU or PSU fan that is noisy? I see that some DFI boards have DC-in jack, that would be ideal.