Not sure about the old Lousie but I don't think the Julie (which was before the Julie HP) was very well thought of.
Wiggle has some ex-demo Julie HP's for around US$67: http://www.wiggle.co.uk/p/cycle/7/Ma...ke/5360040203/
I have those old Louise sitting in my garage. They are good enough brakes and you can get replacement pads on Ebay for cheap. My only caution would be that they have a single piston so you need to keep an eye on pad wear. One pad is stationary and if you let it wear down too far your rotor will rub the caliper. The other pad moves with the piston and will have to be turned in every once and a while when your lever gets too close to the bar. Depending on how much you ride and conditions, you shouldn't need to adjust more than once every couple weeks.
How about these:
I know they're white and don't come with hardware or adapters (if you need them). But you LBS should have hardware (ebay does) and pricepoint.com carries the adapters for less than $10 each.
Just a thought...
I should have also mentioned bikewagon has an ebay store, as well, that carries more disc brake sets than what they show on their website.
I have no affiliation with bikewagon, but have recently purchased those Magura Louise brakes and have been very happy.:thumbsup: