Your staging set is critical and may vary from one concert venue to another. If you are looking to get a good recording or just give those judges your best performance you should consider how the band is set up. Get some older directors you respect to listen to your band and try their recommendations. I would give you my typical set up but it varied from year to year. The stage you perform on will present a number of challenges which your band hall may not. Seldom have I found a UIL stage ideal for recording for competitions (except Gladewater).
If possible go and listen to other bands at your contest sites. Do not be afraid to experiment and move kids around in rehearsals. Also, record your rehearsals, analyze, and adjust your seating. It has worked for my bands.