Having shot with both cameras, I agree completely with Brad.
You just can't compare with the low light quality the A7s puts out.

I'm not used to this thread part of the website yet, but I have noticed that whenever I get a reply on a question I have I have to search for it by going back to the question I posted.
Is there a notification anywhere to let me know if I got a reply? If not, could you add one?

Thanks for the tip! I'll make sure to get on of those. I'll probably stick with one of the Zoom's you recommended since I know that format best.
My last question I still need answered is about the preamp.
Do I need one and what does it do?

Forgot to mention this is what I was recommending for a preamp if it is needed: http://www.bhphotovideo.com/c/product/615405-REG/ART_USBDUALPREPS_USB_Du...

My brother-in-law (no experience with film/audio) wants me to teach him how to record his daughter singing cover songs really well.
When it comes to money, think the middle tier. Definitely nothing over $1000, but nothing dirt cheap.
Here's what I was thinking and you let me know if this would work or not.

For the recording device: Zoom H4N (easy to use and setup)
Microphone: almost the same as your NT1 USB. I was thinking this: http://www.amazon.com/gp/product/B002QAUOKS/ref=as_li_tl?ie=UTF8&camp=17...

Preamp: I'm leading this one off with a question. Do I need this and how difficult is it to use? I am an editor and have very little experience with recording audio other than the standard shotgun > XLR > h4n.

Let me know what you think.