i would not like to spend more than $350. i would like good overall sq and spl? would it be wise to hook up my speakrs to that also? or should i get another amp for those?
Definitely separate amps for speakers and subwoofers. Unless it has a dedicated subwoofer channel built into, many amps are "three way capable" where they can power a sub and speakers at the same time but I would not suggest doing that.
As for powering those IDmaxs...are they Dual 4 or Dual 2 subs? And I strongly suggest saving up the money because those are very potent subs and you will not find a amp that can provide the SPL and SQ those subs are capable of with a price range of only 350...BUT I would get the Infinity 1211A.
Look at the amplifiers people are using to power those particular subs, there are JLs, Zapcos, Eclipse, JBL and Hifonics who all make very good amplifiers, but are also a little more than your price range, you can get the Infinity 1211A on ebay for under 350 brand new shipped to your door!
Hope that helps a little, and good luck with an awesome set of subs.