consistent voltage

So how many Amp hours should i be looking for in a battery. If i add another battery wouldnt that put an additional load on my alternator.

higher number AH CCA CA etc deepcycle is pretty much whats ya would want. no isolator is needed just mount the second batt where ya want it and run some 0 gauge to the trunk, hook that up to the second batt, ground the second batt in the rear(and some people put in a run of 0ga ground too but not needed in this low of power). for lack of words it will give you more power avalible to your amps when its needed,like rollin around full tilt and will charge back up when your not... and it never hurts to put a charger on the rear batt here and there to keep it good n charged. ill try n fnd a diagram on how to wire it all if ned be. its pretty easy though and no worries about your stock alt. yeah it might run a bit more but it kicks on when volts drop from anything in the car, headlights, brakelights ETC. if ya think about it to compared to doin one batt up front and a HO alt you might not have the batt reserve so the HO would be working more to keep the single batt up.

What if i were to get two Duralast gold batteries, they have 1000 cranking amps and 800 cold cranking. They dont say how many Amp hours they are.

it could work but the prob with them is you wouldnt want them in your car where people ar cuz they let off poison gasses. lol i know im sorry for puttin down some of the options you bring up im just relaying some info is all. i meen if you want to it can be done but just wouldnt want ya to get sick or any of that. health isnt really worth it to be honest. you can find smaller audio batts for sale cheap sometimes on audio forums or ive heard of yellowtops n that going for cheap on craigslist too.

Oh dont even worry about it, im just throwen out random ideas. The optimas dont let off any poison gas do they.

WallyWorld. Everstart and Duralast are the same battery, made by Johnson Controls (Like more then 3/4'* of whats out there now) Pricewise, Wally buys/sells more than anyone and usually has the lowest price. Yellow/Red Tops are glass mat/gels that dont put out the fumes like the others, but they do have blow offs. Personally I don't see them cost effective. It'* a different technology but don't expect any more longevity than the normal.

What about this as my main battery ? http://www.sonicelectronix.com/item_...N+SK-BT80.html

Should i replace the battery to under hood fuse box as well, while im doing the big 3?

you can but from the mods ive done in my car it isnt needed. my volts dont drop much below 13.9 after a few at full tilt and im running more power than you are.