Nice deal on the IDA-X305, always liked that unit... good price on that for you there too!
anyway, Alpine do a package deal that comes with:
1x MRP-F600 4x100WRMS 4 Channel Amplifier (yes, its a true 100WRMS)
1x SPR-17S 17CM Type R Component Speakers (tweeter positioning is something to think about, they're big suckers)
1x SPR-69C 6x9" Type R Coaxial speakers (Ask your dealer to swap them for SPR-17C for you, i know i do for customers, as the 6X9"s wont fit)
comes to about $1300 RRP, and the pack goes for $999. works out that you get your rears for free.
Good sounding speaker in the $349 range, you can get a speaker with a nicer high end, but the type r really does well, and makes a LOT of midbass.
Mosoto:
Since when are 4 channel amplifiers class D?