You might try temporarily placing something firm but not hard on the existing seat to raise it 2". Try a short ride on that. It will open your knee angle noticeably. Then, you can have the OEM seat modified if you find the added height to your liking. Finally, you can lower the footrests if necessary.
For my 03 Stone Touring, I had Corbin build me a 1" taller than standard seat and I fabricated 1" lower footrests set 3.5" aft of the OEM placement. Love it. Worth the time and expense.
Ralph