RE: Is this a dumb idea??
it depends on which servo it comes with, the S9650 is the futaba servo that most ppl use but I hear the 3400g is also a great one (faster time on 60 deg). The S kit is fine if you're looking to build yourself but it will cost more to upgrade compared to just getting the SE V2 right off the bat.
I don't know that you want to use the spektrum dx6 though, it's strictly for park flyers and doesn't use DSM2 like the DX7 does. you might want to look at the DX7 or DX6i and yes the receiver it comes with it fine. I think the S verson comes with the 430L 3550kv motor unlike the SE V2 which comes with the 430XL 3700kv motor.
if you're really interested in figuring out how everything works you could just get the SE V2 kit and take it all apart to see where everything goes, the manual it comes with shows how to build it from scratch if you need to.
make sure you watch the finless videos on helifreak showing how to build and configure the heli, even has one on setting up the DX7.