Changing giraffe gearing.

Hello, I am thinking of changing the gearing on my giraffe unicycle to make it a bit faster. I have the 5ft Nimbus twin chain giraffe, the sprockets are 32t at the cranks, 28t at the wheel. I’m looking to get a larger sprocket at the cranks by a few teeth, and probably at the same time I’d like to upgrade the cranks and bb. I’d like to keep to the same crank length, or have minimal difference.

I have looked at BMX bb’s and cranks, but most BMX cranks are 175/180mm, so would be too long for my likes. Anyone know of any cranks and sprockets that would be good for this?