I just picked up a rockford T-1000BD, not the new constant power series 
. I'm still looking around for subs but have pretty much settled on two JL 12w3's in a sealed box wired to two ohms. On top of this I have a JL Slash 300/4v2 for my Focal front and rear component and coaxials(respectivly). All running off a Kenwood excelon series deck in my 03 Ford Explorer Sport. What all am I going to have to do once I add the subwoofer amp? I am fairly certain the stock alternator and a single battery will not be able to handle this sort of power load very well.
I would recommend a Kinetik HC1800 battery. Do the Big three for power and use 1/0 cable for future upgrades. You can have your alternator upgraded with a high output kit or mod one from junkyard to a 200 amp. I do not believe in spending the excessive amounts some charge for alternators when you can do it yourself. You could also get a bracket for duals and a different serpentine and you will suffice your power needs. My car pulled 170 amps (on most days but could occasionally draw 250 amp) and was fine with the Kinetik HC1800. I also run a Tsunami 20 farad cap which you could likely live without. I always used caps to keep my amps with peak power and I could set variable voltage from it.
Do not use smaller than 2 gauge in your truck for what you are going to run
You can also put in two batteries if the 1800 will not fit under your hood. If space is a problem use the HC1200 under hood and put a HC600 or HC800 (they are respectively small to put in the rear of your vehicle. I was going to drop an HC600 under my cap in my trunk. Some will tell you that you need the isolator for 2nd battery but you will not be pulling enough power to require it. Without the isolator, your vehicle and audio system will use the power of both batts and you will have ample power. You could go with XS Power, Kinetik or save money and just use a Deka. Use an AGM battery (absorbed glass mat)
Honestly a single stock alternator 200-240 amp modded with high output kit and a single battery will work for what you are running. Run 1/0 or 2 ga to rear and then go from distribution block and run 2-4 gauge in shorts runs to your amps in trunk. I also lean toward circuit breakers rather than standard fuses. I ran AGU in trunk and ANL under hood in the past. Circuit breakers are nice to click the button and disconnect the system easily. You can run circuit breakers to your trunk amps so you can individually kill amps while doing tuning. I had a 300 amp circuit breaker under hood, 200 amp breaker before sub amp, 90 amp before my Zapco, and a 60 amp on my class D. It is convenient to work on like that. I do have stacks of blocks in gold but gold went out of style
also just look at you fuses that are in your amps to estimate your amperage and build accordingly. I think you have 4 60 amp fuses in the RF BD1000 and 40 for the JL. So I would say put at 200-250 amp under hood and use 180 amp before your BD1000 and a 40 amp inline before your JL and you will be all good.
