with a 9x multi you only need 400fsb so plenty of boards will do (my fave is the abit QuadGT @ $160 from Newegg after MIR but it's really overkill for what he needs).
As for the DS3 & 1.8V RAM:
the JEDEC industry standard is 1.8V - any RAM requiring more than that technically doesn't meet the industry standard.
However, the DS3 etc. (& pretty much all other similar mobos) will allow you to supply more than 1.8V.
Usually it's just a case of installing 1 DIMM to get into the BIOS, increasing the Vdimm settting, save & shutdown, install 2nd DIMM & away you go