Just send it Jase

I reckon with your wave background you'll find it easier because we're used to sailing far more upright and with far more front foot pressure than say your average slalom or bump and jump sailor. The foil is very laterally stable so don't even think about that.
You want to be powered so you can generate board speed easily. If you have to pump, in my opinion, this is hindrance when learning because there's a whole lot of foot pressure and mast rig loads that are over exaggerated. You want to be able to just sheet in, get good board speed and be prepared for the lift. That's the biggest thing, as soon as it lifts you have to be prepared to get forward fast and weight that front foot to control it. Once flying, front to back foot pressure should be pretty even, once again much like a wave board with small fins upwind. Trim with the front foot mainly and sail sheeting. Sheet in will drop the nose, sheet out and the board will lift, move the mast forward to accentuate this, and back to reduce it; moving the mast back will also make the foil more 'twitchy'
I wouldn't bother with the short mast, if it was me i'd go straight to the 90, but use the 71 if you're worried about the height (it's not bad). The short masts are just too short and don't have enough room for error in pitch trim so you'll ventilate the main foil a lot, once again hindering learning.
Don't over think it and just remember that a foil is a lot more sensitive to foot load that a normal board so tread lightly but quickly. It will probably fly out of the water initially as you've over loaded the back leg and aren't quick enough to get the weight forward. But if you can recognise this quickly you'll progress quickly. Front foot strap is also useful as it give you a lot more confidence as you can lift up with the front foot and generally feel way more connected. I would almost go as far as saying start out straight up with the front foot in the front strap and rear between the two, closer to the middle of the board. If you look at almost all 'gen2' foil boards they almost all have massive rear volume for this reason.
Lastly i'm not really that familiar with that foil but if they have an adjustable stabiliser, trim it for higher lift other than 'neutral' or less lift. This may sound counter intuitive but trimmed for less lift foils are naturally a lot less stable in pitch. The reasons for this have been discussed in other threads but they all fly a lot easier and with more stability with more 'lift trim', yes the lift will be greater but you'll be able to recognise it more easily and adapt to it quicker.
If I didn't have to work i'd come down and have a session with ya