Revs will wear out the NA build you make... heat will kill the FI.

As long as you upgrade the cooling capacity, going FI is probably a bit more reliable way to make higher levels of power once you get over a certain threshold. The stock S54 makes over 100hp/liter at the crank already and has piston speeds that approach Formula One engines at max rpm. Not much blood to squeeze from that rock, without a cost to reliability and longevity.

If you want reliable, stay NA with basic mods and make sure everything is maintained.

If you want big power and reliable, don't dismiss FI. It will be cheaper and more reliable to reach higher power levels.

If you want badass NA power, then go for broke. Nothing worthwhile is easy and big power NA build is the sexiest way to go, but also the most expensive.