As big as you can still uphaul...8.5 for sure, bigger might require a 220 lb guy to go wider and more volume.
The foil doesn't care.
But if you can pump a 6.3 up to foil, it's lighter and easier to handle than an 7.6 sail.

The 2020 model has a longer fuse which adds stability, but a more 'sporty' wing to be faster. The default 1150 wing I call it the 'psycho wing' because as soon as you start flying it takes off at a speed that seems crazy to me and in gusty wind and chop I find it hard to control: it is not a setup for beginners, but more for progressing to the next level.
For someone learning I think the 2020 model is definitely better, but I would start with a bigger wing like the 1250 or the 1400 high aspect.
I had a session with the 1400 in marginal conditions and love how smooth it is. It takes off almost as early as the 2019 XL and I am sure it has much better top end even if not the same stability in the low end.
Anyone using other wings please post your feedback.

Started using the 1650 (successor of the 2019 XL wind) yesterday as the standard 1150 is quite small for my weight. 75 mast and 320 Backwing was nice and smooth. Predictable lift, no issues on gusts, yet. Low-end is interesting. I could even do some sort of snap jibe before stalling the foil.