Hi Warrior,
I've done about 28 knots on my wave gear, you should be able to crack 30 on your kit.
The secret is:
1) Go deep! Turn well downwind when you have a big gust. This will increase your speed like crazy. You are never going to go fast if you just go straight across the wind.
2) Rig big. You want to feel like you're overpowered when you're going across the wind, this is the only way you'll be well powered going downwind.
Getting expensive slalom or speed gear isn't required to beat 24 knots.
If you have 20 knots wind, and flattish water, then I would run:
Excess 6.9
MFC SL Slalom 36
Allwave 85 if well powered, or the bigger board if you're struggling.
This might feel a bit unstable at first but should get you cranking when you figure it out