I almost forgot, you don't want the amp to warm or colorize the sound when near field mixing, so make sure your amp is flat and matched withyour monitors. I get away with using my crown power base 1 or 2 in my home studio, works well.
As long as your processing the sound at 24 bit's the audio should be good enough for your purpose. Taskcam makes a decent usb recording interface, it comes with cubasis, and is under $200. Check into it, if your serious about building a budget type recording studio. My daughters set up is just a bit more than that, she's running pro tools on her Mbox by digidesign. A hand me down from pop's...

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