First of all, you already have windfoiling experience, this helps a lot, especially with upper and lower end control and pumping. You mention you want to go from 8-30knots. That is not a problem to have one board, but you will need min 2-3 wings and for sure min 2 -3 front wings. So I am 76kg, when I am not testing all kinds of other front wings, my go to setup is Sky Wing 5'0"/75L, mostly 4/5/6 Unit D Labs, although I have other sizes. And my 2 favourite and most used front wings are Aero Free 1000/216 and Aero Free 1250/250. Covers pretty much 8-25knots, up to 30 although then 4.0 and 1000 front wing get quite a handful, esp if salt water/waves.
So I think with your weight and experience, I would go for:
Wings (Unit if more often in waves, jumping/lift is key), or ease of use/boom (Slick SLS) - go for sizes 3.5/4.5/5.5, I think you will not need to go to 6.0. If you really want a 6.0, then go 3.5/4.5/6.0. Front wings go for 1750 Aero High Aspect and add the Aero Free 1250/250 - you can use the 250 back wing for the 1750 High Aspect as you are light (usually it comes as a set with 300 back wing).
Once you have improved, pretty sure you will only be on the 1250, sell the 1750 and get the next smallest in Aero Free 1000...this is what all my local friends here ride too - 1000/1250, mostly all on the 1000 unless very light...sounds small but it is super efficient with a huge range once you can pump.