The Phil Freewheel hubs are what Ive toured on for years,
I'll agree the cassette hubs are way up there in price.
Phil had the adaptation of a higher left flange than the right, so the same spoke length works for both sides ..
I built a 48 spoke rear, so when 1 spoke gave out, the 47 remaining worked fine.. a trifle of re truing and I was on the road again..
borrowed a big spanner later pulled off the freewheel, and replaced the 1 broken spoke ..
Don't know of the bike shops in Belfast or Dublin, these guys
http://www.sjscycles.co.uk/default.asp
are here : 91-93 St Johns st Bridgewater, Somerset, TA6 5HX
How bout dump the whole derailleur thing and Get a Rohloff hub & simplify to one chainring ..