Class D is more efficient than class A/B.
For example Alpine's class D amps are about 80?fficient. That's a d**n good efficiency.
I own a Rockford Fosgate Punch 325.1 amp. Its class A/B and if 66.7?fficient.
The more efficient the better. Class D amps still take power from your charging system but less and in a more efficient manner.
If you get those two subs, add up the total RMS.
They are 500RMS a peice which means it would be best to find a mono amp that puts out 1000RMS at the proper impedance.
There is an alpine amp that puts out 1000RMS @ 2-ohm but less at 4-ohm.
The PDX1.1000 puts out 1000RMS @ 2-ohm AND 4-ohm so this makes it possible to use any wiring basically.
What you want to do is ignore the 1500W. Don't go by peak or max values. Go by RMS. That's the nominal power the speaker should receive. You will only need one amp that is 1000RMS at the proper impedance. Also, you ALWAYS want cea compliant amps. This means the amp WAS tested for true power and PASSED. Sometimes they have even MORE power than is stated.
Alpine is all cea compliant so you won't have to look for the symbol.
1000RMS will be LOTS of power and LOTS of bass. I really recommend an alpine amp.
Knowing that the Type-R woofers are dual voice coil, You should buy two of the 2-ohm woofers which ends up making a 2-ohm total load.
I would not recommend the Alpine V-Power MRPM1000.
This amp gives off a full 1000RMS @ 2-ohm, perfect for having the dual 2 ohm type-r's and this amp costs half as much as the PDX1.1000.
Hope this helped good call with looking into Alpine, they rock!