D*mn, wrote a whole book here, then got a server error.
In short: 95 amps at 12 volts is 1140 watts. Continuous power!?
Mind your ears! What? MIND YOU EARS! WHAT? ...
If you plan to go only full power at demos or festivals: get an external power source.
Capacitor: at these high currents, ALWAYS use one or more capacitors. It will flatten out the very short current peaks that make you interior lighting go flicker. Go for decent capacitors. High temp range. Don't be fooled by gold plated terminals or voltage indicators. You won't hear them...
Extra battery: gives extra power for a certain amount of time. Get an extra battery and put it in the back, as close to the amps as possible. (Same goes for the capacitors BTW.) Do not buy a car battery, as they are designed to give high peak currents for the starter motor and glow plugs (in a diesel). Go for traction batteries, as used in e.g. UPS systems, solar power systems or forklifts.
Alternator change: take in account the extra load on the engine, the driving belt, bearings,... You might consider a minor upgrade. I would not do that.
K.