Needed electrical upgrades for 4 kicker cvr subs in sealed box with a hifonics bxi2006d?

i am planning on getting 4 kicker cvr subs. 12 inch. i have two 2010 models now but getting 2 more 07 models. each sub is rated for 400 rms max. im getting a four hole sealed sub box with about 1.15 cubic feet of airspace in each chamber to put them in. im planning on getting zero gage wire and i have already did the big three. im planning on getting the hifonics bxi2006d. which will prob push 1600 or 1700 rms because they don't do rated power. i have a 105 normal alternator. im wondering all of the electrical upgrades i will need to do to power the amp and not harm my cars electrical system. i prefer not to buy a new alternator . just saying. dont know what kind of battery i have right now though. its not top of the line though.