Re:
The site linked with the database has both the front and rear hope hubs in, but measure to be sure. To be honest the hub differences of a similar size only have a small effect, rim has the buggrst if you get it wrong. You have the erd (mavic quote for something slightly different so add 3mm to it).
I know the site quite well as I added a lot to it and chatted to the bloke about stuff. It is all based on the same calculations as per spocalc excellent sheet as should most spoke calculators. It is just a bit of trigonometry in the end.
What varies between calcs is where they decide the spoke should end.
Do you have any spokes to hand
The 260to 269 are the standard length you find with 26" wheels. Most around the 264 to 267 length . 32hole 3x. At least for retro rims.
I placed the hope dimension in the wiki to, direct from the old hope sites.
Twisting spokes alters thing a lot and no calc I know caters for it. I guess it depends where you wish to place the nipple end number if spokes, thickness if spoke at the twist...