MM2124 + BXi1206D = Good combo?

I am ready to start upgrading the "system" in my 04 Monte Carlo.

I currently have:

Stock head unit
Rainbow Dreamline 6.5" components-front
Polk Audio EXII 6x9's-rear
Obcon 12" subs in ported Obcon Godzilla box
Obcon 300 watt amp for subs
Mids/highs are being run off stock 200 watt amp(which gives full output at 2ohms)

Mids/highs aren't nearly as loud/crisp as they should be since the speakers are 4ohms, although it is quite an improvement over stock. Subs are suprisingly competent considering I've never heard of the brand before in my life, although they surely could use alot more power. The box seems to be the best part of this "system", very sturdy, well made.

My plans are:

Pioneer DEH-P880PRS head unit $350.00
Keeping current interior speakers
2ea Polk Audio Momo series MM2124 12" subs in a sealed box $200(subs only)
HiFonics ZXi 6406 85 x 4 @ 4ohms (mids/highs) $240.00
HiFonics BXi 1206D 900 x 1 @ 2ohms (subs) $260.00

Is that a good sub/amp choice? My goal is to have a system that looks good, sounds crisp, and can hit hard and clean. Money is an issue, so if you recommend other products, make sure they are the same or lower than the prices of my current selections. Thanks for your help.