Hey mate
9m evo probably better than mono at your level. Will feel stabler and better in 20kn.
Board size sounds ok
Kite size ok - but learn your functional window, probably steady 15-23kn at your size.
and don't go out in solid 25+ knots on the 9 in your first year.
Ie. if everyone down the beach on Twinnies is on 5-7s, except the 110kg guy on the 10m, don't pump up.

Have fun, respect and be safe