I got mine direct from Jekylls with Matts blessing. Not cheap but well made and a good shape. Jekylls had the measurements but Im sure Matt will let you have them if you go elsewhere. As standard it came with various loops and rings for a retrieval cord. These may be useful if you use a chute in the foredeck but most of us just pull it back into the cockpit. You may save a few bob by asking your sail maker not to include these fittings.

Ive tried various double (violin) blocks for the halyards. You do need something strong as the jib halyard has to go on the lower and smaller sheave. I think the one I have on at the moment is a Lewmar. I dont feel that the Barton offering is up to the job as the supplied strip-shackle distorts and Ive seen a shattered sheave on another BayRaider.

Hope that is of some help. PS. Ive left out all the apostrophes on purpose to avoid rows of forward slashes. Its not because im a greengrocer.

I think Andrew Denman in Australia has used the new BR Expedition demountable bowsprit to fly a gennaker and/or flying jib.