I've chased cooling issues on my '67 Firebird over the years and have spent lots of money on fans, radiators, snake oil coolant, etc... and what I've learned boils down to this:
Large clutch fan & shroud* > SPAL electric fans > any chicom electric fan.
*(Although modern PWM brushless fans have pretty much caught up and may be the best choice)
Straight water is the best coolant, but you need an additive to prevent corrosion & lube the water pump.
The faster the water can flow, the better it will cool. I.e. No thermostat > thermostat > restrictor.
(The science behind it:
heat transfer coefficient)
Here's a post I made a while back on cooling with a little more detail.
The Ultimate Cooling Thread