I'm a rep for a HO alt so I can get you a alt at a discount price.
Pm me if interested in a quote.
This is the same brand of alt I used Im my eclipse I had just a 170 amp alt (which was very underrated, it actually did 210)
I had 2 sundown 3500ds at .4 (clamped 8980 rms) on 2 hd 18s and 9 Kinetik HC16vs, my voltage never dropped below 17.5 (starting voltage was 18.8v)
I did 45 minute demos and lowest I ever saw voltage was 17.5v full tilt!
Many competitors use them.
The company is called MAE Alts.
Pm me if you want a quote.