Forget the power ratings they're meaningless unless they tell you *what* the test conditions were. It also doesn't mean anything more than how much power you need to burn the voice coil or damage the suspension... not too useful.
40 watts should be more than sufficient, provided it's tuned correctly and located in a reasonable location (non obstructed). 80 watts can be even better in terms of tuning flexibility, although it's doubtful you'd really use more than 40 on a continuous basis.
I'd stick with the Seas, and lpg. Peerless is nice, but not the one's you've chosen and I've never really been a BIG fan of their tweets You can cross the lpg over at 2600hz, not a problem. It's just not ideal because of the rise in distortion (which many people can't even hear in a car).