I used an 8" Norton's Mill Bastard file. I would get the 10" (I have one but its still in the package, didn't NEED it). The 10" will just be more stable, so if your buying one, get the larger file.
Smooth file might be ok for finish draw filing, but the Mill Bastard is your standard file, easy to come by, and does a good amount of removal. I like the Norton brand, made here in the USA, and are a good quality file. I tend not to buy lower brands/store brands. I believe Brownell's also has a specialty draw-filing file if you want to spend more money than you need to!
Agreed you NEED a file brush, and some cheap blackboard chalk. Make one pass with the file, move it over to a clean spot on the file, make another pass till your at the end of the file, then brush the teeth clean, and fill the file back in with chalk. I did this and really didn't get many gouges that were not my fault...
Then "polish" with 220 grit wet/dry just to smooth the finish out. Use a flat backer, the file works, I have a wooden sanding block that is flat (planed flat) which worked well. This surface will be perfect for browning, IMO. I'm going to cold blue mine, however.