is a new alt needed?

where could i get a good high output amp alternater from at a good price? and the car it will be goin into is a British Vauxhall Corsa, some people may know it as Opel! the model number of the current alt is 90 389 246!

i will be running

will all of this is a 200amp alt enough or will i need a lower or higher 1?

200 should do it but u have no idea about a H.O. alternater for that car try a search online and also you can try www.highoutputalternaters.com they may beable to build one for you if you send them your stock alternater

IF you have any Auto repair shops locally that deal with auto electronics like: Starters, Alternators etc.. you might be able to take the stock one to them and have them custom rewind the alternator to the higher output