2nd battery needed?

I have a pretty simple question.  My truck (97 Chevy) is running a little short of power.  I will be installing a 200 amp alternator on Monday, but I have a question on whether or not to run a second battery.  I am currently running a MTX 81001 at 1 ohm to four Alpine SWE 12" subs.  I am also running two MTX 302's to my highs.  I have a Power Accoustic 2.5 Farad cap with a built in volt meter and amp draw gauge.  At full power (approximately 2400 watts) my voltage is dropping down to around 9.5 volts at the cap and shows about a 100 amp draw.  It does not kill the truck, but it takes about a minute after turning the stereo down for the voltage to return to 14.4 v at the cap with the draw at about 4 amps.  Will the 200 amp alternator be enough to keep up or should I consider running a new battery or possibly two batteries?  I do plan on running competitions but on a very limited basis.  It is more for personal enjoyment(as well as those people within a three block radius).  What do you guys think?

HO alt should do the trick, unless your doing a lot of listening to it with the car off.. then the Alt isnt going to help you.

um how is he going to fry the electrical system???

an ho alt. should do the trick... but if your running a stock battery put an optima red top under the hood.. upgrade the BIG 3 otherwise the ho alternator is useless... if voltage still drops you may need another battery as u have a lot of power and it will give your system more stored power and the ho alt will have no problem charging the 2nd battery..