If you want low without going to the extreme of clubmans or clip-ons, then what you're looking for are drag bars (no rise and very slight pull-back), or euro sport (2" rise and slight pull-back).
As for suppliers, if you don't already know exactly what you're looking for when it comes to measurements, you're probably best off going to your local bike supply shop so you can actually look at the bars and maybe even take them out to your bike so you can get a better idea of what they'll look like when installed.