Big 3 and Alt/Battery Upgrades?

Here's what I have:

99 Tahoe
Premier DEH-P980BT
2 Kicker K650.2 Componants
^running on ZX250.2 (85w x2ch @4ohms)
Kicker CVT 12"
^running on ZX400.1
Viper 5900 SST (not sure if that matters)

I'll be changing my sub to either one or two CVX 12"s soon. If I do two, it'll be 1500rms, if I do one it's 750rms.

I figure if I just do one CVX, I'll do the "big three" wire upgrade and I think I'll be fine. If I do two subs, will I need to upgrade my battery and alternator?

Will possibly be adding a couple 8's in the future, adding maybe 200w.

I'd like to avoid the expense of the battery and alt. I'd even like to put off the big three if it's not necessary. I'm getting different people telling me different things. I'd like to hear what people in here have to say.

If you go up to 1500 watts I would at least do the big 3. As for the battery & alternator you could potentially hold off and see what happens. It also depends on what type of listening you will do. Will you be listening to the stereo quite a bit with truck off? You might do pretty good without a new batt/alt until either one of them starts to die then you will probably run into problems.

I am running 2000 watts rms and am in the process of upgrading to the big three and as soon as I get some money will add at least one battery (maybe two with an isolator) and a high output alternator. But I also plan to be running the stereo for extended periods with out my truck running.

Thanks YukonMud. I don't listen to my stereo much without my truck running, so I guess I'll probably be okay. I'll probably do the big three either this weekend or next. I'm glad I can hold off on the deep cycle battery and H. O. alt. They're a little steep.

Those High Amp alternators sure do cost a bit. My system was pulling so much power it was shutting off my truck. Which is very inconvenient when rolling down the road, or off-roading which happened a couple times. I put a 160 Amp PowerMasters Alt in and It's awesome. $260 from Summit.