I've noticed the sad news of the impending closure of well established Uk self build forum.
I suggest Fubra offer to take it over & add to Hpc's own Self build forum as it needs a boost .
Ebuild forum has a ready made community in this growing sector. It compliments the aims of hpc'ers & forum uses similar software to ease the transition.
Edit
I noticed this,, so my suggestion may be a bit premature
http://BuildHub.org.uk