It really depends on the skill of the rider, Last summer i rode ALOT and my biggest kite is a 12m and i use a really big board 145x143. I weight about 155 pounds. If you are looking to complete your quiver with 2 more kites i would suggest a 10 or 11 and for your big kite a 13-14.
I dont think any bigger is necessary. With a 12-14 meter and a big board at your weight you should be fine, any wind less than that is just boring anyways
