Channels 1 through 8 have inserts on them. They are pre EQ and pre Fader.
Using them, you would set your levels via the gain knobs.
Your thinking of them being FX loops is correct, but that's not all they can be used for. They can also serve as direct outputs for those 8 channels.
Though if you insert a regular TS cable you will interrupt the signal from going through the mixer. However, what you can do is make your own cables that are TRS (Tip, Ring, Sleeve) at the insert end and TS (Tip, Sleeve) at the other end .... with the leads for the Tip and Ring connected together and soldered to the Tip of the TS plug.
This will effectively give you direct out without breaking the signal through the rest of the mixer (so you can still direct monitor what you are recording).
Then you could just get you a
Delta 1010Lt for just over $200.
However, with your custom insert cables you would need to use Male RCA plugs instead of 1/4" TS plugs. Wire them the same way Tip and Ring leads to the center prong of the RCA and Sleeve to the outer ring of the RCA plug.
If you aren't up to making your own cables you can just buy 8 of
these 8 of
these.
This setup will give you a total of 10 pre-amped channels into your computer (8 from the mixer and two from the 1010Lt). Not bad ... and much greater flexibility than the ADA8000 and an ADAT interface card (like in my previous post).
Trust me, as a fellow drummer, if I were you I would get the 1010Lt and the appropriate cabling to use with the mixer you already have.
-Ken