yes, his are custom made and I know he has just restocked recently unless they have been sold. The headbolts im using are again Sitech spec re-usable ones.
for the prices you need to speak direct to Simon for exact amounts, you can get him on 01796 481 495, i would recommend giving him a call as he will answer all your questions in a matter of minutes

Hope this helps mate

p.s. post the spec you are building, im curious (mainly nosey)

Raj