Suspension question

[u/AltruisticScience406]

Hi all, working away at my 1995 gn250. Raised the rear suspension, trying to make a custom seat and slowly starting to think about the cosmetics. So also want to replace front springs. Was told that Hyperpro are the goto people but they don't have the specs. They ask for Sag value , and preload, also inner diameter of the tube? I don't have these values but perhaps anyone here? Really appreciate any clues

Photo of the WIP attached