Some of the ILM X-Wings were painted flat black first, then gloss white, and then that was weathered down with steel wool or something similar to remove the gloss and let some of the black start to show through again to get that light grey look.What's the steel wool trick? Are you roughing it up in preparation for paint or is it a weathering tecnique? I'm about to build the 1/48 version myself.
Especialy since you are working on a 1/48 scale kit, I would go with the finest you can get.The finer the better. You can control the amount of weathering better that way. At first I used whatever I had laying around which was prob kitchen grade stuff and that almost took off all the color with one pass.