i need some help in choosing a new home amp...

[ChesterFuzzin']

right now i am in the midst of deciding which power amp to get to replace the one got now.. but i have a couple questions that i need to figure out b4 getting the power amp..

im deciding between 2 different's amps to power my subs..

the first amp is a jvc jr-s501 receiver ... 480 watts max (8 ohm), 4 outputs, as an equalizer with a band slider for 40 hz, super old receiver from the 70/80's that weighs a ton..

and second amp is a pyramid pa 600 amp, no equalizer.. 600 watts max (8 ohm), speakers A and B

my question is for amp/receivers that have a speakers A and B configuration. basically, am i correct in assuming that in speakers A+B mode, its 600 watts max/4 = 150 max per output and in speakers A/B (A or B exclusively), its 600 watts max/2 = 300 max per output?

my second question is would there be any advantage at all in
picking the old school jvc over the pyramid?