alternator power help

[tpjaws]

hey all, going to get a new alternator/revamp my old one, and want to get an ammeter gauge to monitor its performance, but i dont know which gauge to get. one has between -30 and +30, and another has between -60 and +60.
ive heard that the standard alternator only does around 14 but i am running a small-medium sized install (3x10" subs,2400w amp,power cap, redtop second battery, 2nd amp,4x13.5cm speakres,10xtweeters,4xcrossovers) so im thinking i may need the 60-60 one rather than the 30-30 one....
what would you guys suggest?
cheers
Tim

[midge]

i have 3 good alternators.

[tpjaws]

you got a bit of everythin midge lol.
mine is ok but the sound system will blow it and any other up unless its revamped or new.
any knowledge on the ammeter gauge problem or alternator power?