I might be getting picky here, but I would say to look for another amp. You are going to be maxing out that amp big time. Sure, it is stable down to 1 ohm (which you would be running at if you went DVC subs with 4 ohm coils, but more on this later) and you would be gaining nothing by running it at 1 ohm over 2 ohm as the amp is limited in power to 900 W RMS (it will output 900 W RMS at 1 ohm or 2 ohm, just pulling more current at 1 ohm, leading to the amp running hotter, leading to an earlier failure than if run at 2 ohm).
Also, keep in mind the electrical system. Installing the amp at 1 ohm loading, if you crank up the stereo, you are going to be pulling roughly 90-100 amps just to the amp. The likelihood of having alternator overload issues is very high unless you have already upgraded to a 200 amp alternator. so, keep that in mind when installing the amp. That is an additional expense you will be looking forward to in the near future unless you dial the amp down (then why buy such a big amp?, just saying).
Option #2 that I will toss out there is to run the amp back at 4 ohm (ie, running each DVC in series and then running the speakers in parallel with each other). The benefit of this is that the sub will have a better long distance travel and actually get a little better sensitivity out of it (ie, won't need as much power to play loud) and also improve the clarity of the speaker. Granted, this will also mean that you will only get out 500 W RMS total. But, what other amp are you running in the truck? You would be needing to be running about 100 W RMS to each of your 6x8's/6.5" speakers in the doors to match up appropriately to the subs even at ONLY 500 W (4 ohm setup). If you are up at 900 W RMS, you are looking at 200 W RMS per door. That's a lot of power in my book.
Just trying to make sure that you get what you are wanting in the end. I hate seeing people play the perpetual stereo swap game until they finally hit on something that works for them. Much easier to do a little bit of planning ahead of time and buy things 1 time. May not get it as fast, but will save you a lot of money in the long run and save you a lot of grumbling too.
