Yeah boards are hard to choose. My first board was a 160 * 37 cm... I am only 72 kilos so did the job, a dude on the beach that’s another 45 kilos on top of me.. Is using same board (not one I sold him) and he is struggling most of the time even on a 16 meter kite. Going to let him use my 150*43 cm board as that’s really what he needs.
Anyhow.. it’s the width that’s important, been ridding most season a 122*38 board and its the bee's knees over 18 knots with my ten meter kite but under that wind rang and I hate using it because its just a tack up and back affair to hold ground

boring!
Today in 15 knots using same kite with a board that’s 132*40 cm and cruising upwind and down the line wave riding... its added another 5 knots to my kites low end, board size depends on your size and kite size and wind range...lots of variables huh!... something between 128 to 148 long and 40 cm wide.. Seems pretty good from my personal experience.

you might be able to get a new kite as you might be able to knock a few bob off the price, now the silly season almost finished its stock the shops are holding onto which will be superseded by the time the next silly season comes around. Comes down to what your willing to spend.
Use search to find out previous posts on kites and recommendations to newbie’s - at the end of the day... if it looks like a kite... flies like a kite... it’s a kite

…but ideally get something that isn’t more than a year old!
Have fun