hi there, no worries - yes the 2000 High Aspect would be the better choice to learn and especially progress on, with the 3.0 Alu mast and 78cm fuselage set. 82cm or 90cm masts usually good sizes to have, unless you have a lot of shallow waters, then 75cm.
Re the boards, I try to advise people to get a few lessons on bigger boards first/rent or borrow, as you tend to progress much quicker than in windsurfing, it's also easier to pump a smaller board up onto the foil than a bigger board (bigger board will obviously be more stable and "float" up onto the foil in wind).
If we are taking about the 2022 range, as a first board with no lessons etc - then yes, the 6'3" at 140L will be the easiest board to learn on and progress for a few months. If you want to fast track and have a board that you might keep for much longer, then you could take the 5'8" at 125L, but with zero foil experience it will be harder to learn on? the good thing is, the sport is still fairly new, lots of demand, so selling bigger entry level boards is still pretty easy within the wing community.