For your board size, width is better than length.
I ride Shinn boards when I'm TT
Use this as a good guide for their boards - https://www.shinnworld.com/whatssizedoineed
If you go for a big board, you'll find some days it's too much. But, a big board will be good for when you are better and you can use it as a light wind board.
When I was 238lbs, I lived on a King George (146x46) for my first year, flying a Zephyr. even when people were out on 8m kites
But bashing out through waves was hard work on the legs/knees
Now I'm 206lbs I ride a Bronq 137x44 (I did demo a 135x42, but found it lacked a little on the bottom end for me, the newer Bronqs have a better low end now, so a 135x42 might well be a better fit)
Boards are a much more personal experience, demo, demo, demo. Trust me, I spent a lot of money on the wrong sized boards because I listened to 150lb kids working in the shops.