beta reader for middle grade fantasy

I've finally managed to work up the nerve to ask for a beta-reader, after my family member betas told me that my novel wasn't exactly...polished. Which is probably true. But I need a bit of guidance on what parts I need to work on, and feedback on whether my characters and voice are consistent, whether I describe enough, and if I have any plot holes. Above all I just want someone to read it and comment on whether its ready or not to be sent out, and whether you like it. I have the biggest trouble distancing myself from my work, so I have no idea how much more revision it needs. I sent the first queries out last week... but now I'm torn on whether to shelve my novel entirely, take a very long break from it, or resume querying. I was hoping a beta would input their opinion on that.

Info on the novel: about 74,000 words, upper middle grade. It's a fantasy, with lots of magic and portals and parallel world traveling.
Here's my query: http://www.absolutewrite.com/forums/showthread.php?p=3895459#post3895459

I would feel more comfortable if you've are an active, oldish AW member, just because I'm super paranoid...

Anyways, if you're interested PM me.