As started, I have a 2005 Cavalier LS (automatic) & need a better alternator than the stock 105 amp.

I recent installed a sound system & am getting dimming lights on my dash.
It doesn't do it as much when driving at 45+mph, mostly when idling, or low speed / stop-n-go traffic.
Dimming is much worse with headlights running.

Anyhoo, I have a Kenwood 1000.1d @ 2ohm, pushing one Sundown 12.
500w RMS / 750w peak.

The only upgrade alt I found online was from MechMan & was 250a...
That seems overly excessive & not what I need... (Nor can I afford $400+)

So is there any other options for what I need?
-- like a alts from another vehicle that'll work, or somewhere online that has what I need?
I read a thread that was a bolt on from a truck, that required little modification, but was for a 92 Cobalt I think...

Also, thank you in advance for any help.

If you look online for re manufactured ecotec 2.2 alternators, you will come across several sites that offer new/rebuilt 140 amp alternators. Just make sure they are for either a cavalier, grand am, or non forced-induction cobalt and you will be fine. (The alternators for the supercharged/turbo cobalts are designed to spin the opposite direction) I purchased one off of ebay with 2 year warranty for $110 and installed it in my 2004 Grand AM SE and it works flawlessly. I did have to splice in the wire connector from my old alternator, but otherwise, it was plug and play.

Also, for what it is worth, I am running a JBL 14001 mono amp on the sub (1500 wrms) and a Clarion xr2420 on the front components and get almost zero dimming at full tilt and idle. I am running 0 gauge wiring and big three, on a basic 4 year old battery.