I don't know if you are going to use bike hydraulic levers or not, but I found these on ebay for $30 for both left and right. I bought them on Tuesday and they arrived today. They are missing the brake switch, but they cost like $2 each so no big deal. They are the correct size for bikes or my scooters.http://www.ebay.com/itm/151373413004?_t ... EBIDX%3AIT
Here's the brake switches.http://www.ebay.com/itm/4-Micro-Brake-S ... XQC-tTGiav
They are smooth and they come in sets. Hunting around for a matching set used to be a royal pain. Now a few companies are pairing them together for us and still selling them at reasonable prices. I think the brakes on my blue scooter cost me something like $24 each and I had to hunt around to find a left and right matching pair. Also these ones have a site window on them so you can see if you are low on fluid without opening them up. My old ones don't have that. They use 8mm banjo bolts.
This is the brake switches on my old brake levers. Get some of these for the new levers.