that 140amps would be at the high rpms.
Its only 80amps at idle. So it should average 120ish.
It doesnt look bad,Looks like a Delco, probly cheaper than Napa too.
But it might add up after shipping the heavy bugger.
the stock ALT are around 100-105amps.
Most I replace with a 110-125amp depending on what been added.
I buy most of mine from some who I know who rebuilds alt/starters all day long. that would suck
So I'd try and get one at least 110amps, and one 120amps if you are going to be adding big Amps and speakers, AV equipment.
Over All that Powermaster does look like a good deal, just make sure it has a good 1-2yr warnty, and how much it is to ship that heavy thing.
Just looked over at NAPA thiers are $130-180 depending on what engine.
Wasnt sure if your 93' was a 4 or 6 cylinder.