I have no first hand experience with wheels 'cause I've never had the need. But from the descriptions here it sounds like you need a wheel that allows you to tip the bass towards you to roll it, then stand it up on a rubber foot so it doesn't roll, right? So, if the fork that carries the wheel extended down past the axle then turned 45 degrees or so and terminated near ground level at a rubber pad like the brake on a rollerblade, would that work?
(Does my description make any sense?)
Does the wheel swivel on the pin when you're travelling on it?