Some things to ponder...
Most guys install std parts store thermostats. These are the flat discs, with a wax pellet and about a nickel sized hole that opens approximately 1/4". It doesnt flow mutch, and there is very little force "pulling" the center open. At highway speeds (rpms of 3K or higher) the flow from the water pump can be strong enough to push the T-stat closed. There are units called "balanced" thermostats. They are always brass, come in 160, 180, and 195°, and use a tapered larger diameter passage and plug. They are not susceptable to the pressure closing, and will stay open at high rpm. They also have more flow area for the coolant to move thru, so it's not as great a restriction.
Circle track racers dont use T stats for that reason, but they do use restrictors. Unlimited flow can lead to overheating of components even tho the coolant stays cool. There is not sufficient time for it to pick up heat from the iron, so hot spots develop. The size of the restriction depends on your cooling system performance, and will need experimentation to get "the right one" for you should you choose that route.
The A/C condensor takes hot gas, and cools it to a liquid. The reason this works is heat is removed form it, and transferred to the air, which then runs right thru the radiator. So, it effectively heats up the air that has then to remove the higher heat from the radiator. It makes the radiator work harder to do the same job. (I know, you already figured that out...lol)
The electric fans can move the air most cars need to keep cool with efficient radiators. Brass fins and 2 cores are not very efficient. So, in some cases, the electrics cant move enough. Also, I see in your picture...There is more than 40% of the flow area thru the std core radiator is blocked by your shroud. A simple fix is to get some lightweight rubber, cut some sqaure holes about 2"x4" in the solid sections, and screw the rubber to the shroud, overhanging the holes you cut. When you're bombing down the road, the air pressure will force the flaps to open, letting air thru easilly, and when you're stopped and the fans are on, the flaps will seal up, and keep the limited flow where it needs to be. I saw this on a Griffin setup..works great.