Thanks for the replies.

Actually, programming is what I do best :-) I plan on purchasing a Roboteq BL controller.

So the most "difficult" part for me is to find the right motor, given the specs above.

A BL motor working best at 12V, not burning with 5A in the veins (~0.5-1 N.m), with Hall sensor... and that can be controlled thanks to the Roboteq controller ...
is all I need.

Finding a Stepping motor that fits those specs was pretty easy.
Unfortunately, finding a BL motor seems to be a much harder task :-(