Heat management for bigger boost is one of the most critical aspects (along with correct fuel delivery).
The side mount is an upgrade from stock. The big improvement that needs to be done at the same time is the shroud and fan. The problem with side mount is heat soak from the engine bay. Heat shielding / fans is critical. Lots of builds are going boot mount cause of the massive difference in heat soak reduction by being in the boot. You can reduce heat soak with measures to stop radiating and air heat.
Steve has gone for a big strong build so needs the bigger core (plus lots of heat shielding and water/meth if it was me with unlimited funds - lol). Admire the build Steve.
How big is your build? How hard do you want to run the mr2 when it's above 20 degrees?
I am still in build mode and reading all I can, have a high flow ct26, upgraded fuel, other little mods, aim is 18psi (what I was running before but do it with longevity) and have the racer x side intercooler with shroud and fan (prior to the one your looking at), and lots of heat shielding.
Plan with the difference in costs of side intercooler is external intercooler water sprayer and depending on funds meth/water injection. Meth depending on funds :(