Centurion Fi21 is the king of 21's. Ram-fill, close to 5k in ballast, Opti-V hull. Join the
OFFICIAL Centurion/Supreme Boat Owners group and put FI21 in the search bar, you'll find tons of videos and pics.
I'm demoing a Vi22 today, which supposedly surfs amazing too.
If you have budget constraints check the Axis T22/A22. I demoed the A22 and really liked the wave.
Other notables for massive waves- MB Tomcat 22 and the 21' MBs put out sick waves too. I've seen some videos of the new Tomcat Alpha 22 and it looked sick.
Also the Moomba Max supposedly has great waves with over 5K in ballast, but i'm personally not a fan of looks and size.
I demoed the ATX 22 last year, I wouldn't even consider it. It was very loud and harsh driving, mediocre build quality, and most importantly the wave was a complete let down stock.