be careful with eq's. they should only be used when all other forms of acoustic normalization have been done, ie proper layout, reflections damped, and an eq should generally used to reduce peaks, and not elevate nulls. i would recommend at least a 1/3 octave eq (30 adjustable frequencies), and a way to accurately measuring it (the good ole radio shack spl meter isnt a great idea for this because its not too accurate about 10000 hz... )
but when done properly, an eq can make a system go from sounding good to absolutely amazing.
and to answer your question, eq's can be found at most professional audio stores. behringer makes some good ones, the ultracurvepro DEQ2496 is an exceptional one and runs about $380.00
