Most of us have a approximately 12m kite as our biggest and after you get experience this will get you kiting in under 10 knots. Try to find a light kite with three struts or less. I prefer a foil kite but I am in the minority. Then of course you will want smaller kites for stronger winds.
These days wings of between 900 and 1200 cm are popular. This advice is for 165 lb riders. Short masts are popular for the first few hours of learning but you can learn on a full length mast too (I did and most of my friends did). Some first generation foils by liquid force and slingshot may be available cheaply but you will outgrow them.. on the other hand they do work for learning. Lessons are always nice but if you are a competent kiter you can probably figure out foiling by yourself.
I have been kiting 28 days on my hydrofoil at Jericho so far this year and very few of those days were windy enough for twin tips. Today at least a dozen of us got out.. all on hydrofoils.
For me, 80 kg on a 1,000 cm2 front wing, it used to be a 10m OR Flite in marginal conditions, then 6m and smaller BRM Clouds in stronger winds. But having recently tried the Ocean Rodeo 10m Aluula Roam in some incredibly light air all the way up to way over-powered on foil, the Aluula Roam is worth its foil-like cost.