www.z1enterprises.com
~15 bucks plus shipping for the bars I have now.
Be careful, you'll see all kinds of stuff you didn't even know you wanted to buy on that site. Best place for KZ/Z1 stuff.
As for control/cable room problems, the superbikes have all the room you need.
I was very tight with the drag bars. I couldn't rotate the front brake control to exactly where I wanted it, as it hit the top of the fork.
I don't know about the clubmans, but I would imagine they have a whole 'nother set of fitment problems.