I'm building a 4 wheel bike that rides on old RR tracks and I need to figure out a handlebar design.

Close to what I'm building

My seats are generic Wal-Mart boat seats and sit level on the frame. I'd imagine I'd be looking for a handlebar similar to what a recumbent bike would use.

Here's my rig:

I do need the ability to mount brake levers but also need it to be comfortable.

You guys have any suggestions on which style and best way to mount?