Essentially BMXs come in one size. It’s not like MTB where you have 16″, 18″, 20″ frame, etc. There may be little variables (just like similar sized MTBs), but they all run 20″ wheels.
Surprisingly, there seems to be a lot of people in here into the less common variation, the 24″ wheeled cruiser. Which was always a racing bike, within its own category. But I wonder if they’re less common with the MTBers purely because 20″ wheels are so friggin hard to ride when you’re used to 26″?? Because that’s what I’ve found in the past. Wobbling all over the place. It’s so different.
For that reason, I’d be tempted by a street/jump oriented MTB ….but then again, a BMX is great fun. You can chuck them all over the place and they love it..