I imagine there might be somebody there that could work on cues. When I went to the singles regionals in Marietta,GA,there was someone working one and regionals is nowhere near the level of nationals as far as the number of players. If there are going to be thousands of players at nationals,there is bound to be a crap load of billiard supplies and services available.
BTW,what are you going for? My eight man 8 ball team is going and I nearly made it for 8 ball doubles with the captain of my other 8 ball team.