Audio interface for Logic for under 400 ish

I am looking to get an audio interface for my mac pro (So it could be a card or an USB or firewire interface, for specs see my signature). I need it to have at least two inputs, and one needs to be a guitar one but also it needs to be able to be an XLR port cause sometimes I may need to bring in two mics at the same time.

I have been doing midi stuff for a long time and finally got into actually recording things. I have logic and am quite proficient in it so I'm not a complete noob, but looking through all these products I really have no idea what to pick. Originally I was looking at spending no more then like 150 but then I just kept looking and... Idk, I'm getting lost in the mass of these things. Anyway, I have the M-Audio AV 40s and a couple of nice headphones. What I would love is to be able to send whatever sound I like to whatever output so I could have singer one hearing... Himself and something else, and the guitar player hearing... something entirely different, I know how to do this in logic but I obviously can't because I only have one output.

I was thinking of getting this although it only has a few outputs
http://www.bhphotovideo.com/c/product/403523-REG/Alesis_IO_2.html#features
But I would be willing to pay a lot more for a better product. Somewhere up to 400 at most. Oh and also... Balanced and unbalanced? What is this? I have looked it up but..... ugh anyway, any help would be greatly appreciated
Sorry I'm rambling but I really am lost here.

Oh and I would pay more for a few more inputs then two

 

http://www.guitarcenter.com/Alesis-...801473-i1322417.gc?o=5&ipp=25&source=4WWRWXGB
Is this going to record 8 channels separately or is this mixing them down to a two channel thing and then going into my mac? Also the eq controls..... If it's 8 channels going into my mac then what are they or.... Okay so I am a total noob haha