Thanks for the useful info!
Read a lot about the 15" blowing up in the 1540HE, probably as a result of the mismatched power distribution. A friend told me he owned a isovent but it got way too undefined if you werent standing directly over the 10's.
I might go with two separate cabs afterall. Probably go for a 410 HE (though used ones only seem to be able to handle 200w) and hold off the 15" for a while (or go with the 410HLF which seems to have enough lowend on its own).
As for why I'm not going with a 810
1. 410 should be loud enough for a while (is there much difference in tone?)
2. I can't afford a new car