OK ... I was hoping to use my LF2 + M3 but after hearing so many horror stories I think a new mainboard is needed.

I must stick with the M350 enclosure as space is really (and I mean really) tight ... so ...

Do I stick with the M3 & look for a new board

... or ...

get a DC powered board + external PSU - eg: Zotac ION-ITX-A + Carnetix CNX-P2140