For the head I am undecided on a little more advanced, ported & polished 7 bolt like I did for Wildman38 AKA Jeremy:
...or just stick to a 6 bolt for the large, high flow ports. Then do a little cleaning up, knife edging, polishing and the like. Of course if I decide on a 7 bolt block and a 6 bolt head I'll have to jump for the 1/2" or 12mm head studs and make them fit the block as well. These are simple issues though.
I can say I am 100% decided on stainless steel valves, bronze guides and 3mm HLA's as I already have said parts waiting to be used. The valves are sold on eBay by a seller that get's them from the same place Ferrea or Supertech has there's made. They're just not branded, marked or packaged with a brand name. They're the same thing however. This goes from the HLA's and guides.
As far as valve springs go I am looking at Kiggly's High Pressure Beehives. Many people recommend them and like the product. I have yet to hear a complaint about them. Cams are a draw between Kelford and GSC. Size will depend but 272's seem to be a pretty safe number.