Will any Avid brake bleed kit work with my Promax brakes? I need to replenish the fluid in my front brake on my Whyte Portobello (Promax Hornet disk brake) after all of the fluid leaked out through my own mistake. 

I'm looking at kits like this on eBay, will it will be fully compatible with my Promax calipers etc?
The only specific piece that you need to worry about is the threaded hose fitting that screws the tube from the syringe into the reservior port, everything else is identical. 

Unfortunately I believe that the Promax Hornet use two different types of threads for their reservoir ports on the lever and caliper whereas Avid only use a single type (if someone can confirm otherwise, you are good to go). So you may only have one fitting that works instead of the required two.

There are many generic sets that come with multiple fittings that are cheaper than the Avid kit and will have the fitting you need. They don't ususally come with DOT 4/5.1 but you can buy this at any automotive store.