Up to you which route you go and why, but ask yourself what power you want, will you want to keep modding/adding to the car/engine/power, if so forget 40's.
It's a no brainer for me it would be EFI anyday of the week, but I also like carbs, and had plenty tuned cars with carbs.
The adjustability of a decent ecu is breathtaking compared with a carb.
If you want just ignition only ecu just shop around, but some are nearly as expensive as full 3d(fuel and ignition).
You don't need to go the turbo route for more power, but if you think you might end up there anyway work towards that goal, a 3d ecu is a good start, could always use it just in ignition only mode in the meantime.
I prefer and use Emerald K3, junked my L6, best thing I ever did, but mine was mapped by emerald the same people who designed it built it and mapped it, so they do kn ow it well!!
That said there are many other ecu's that will also do a perefectly good job if mapped correctly.
There are some truly shocking people around so choose carefully, mine was set up on L6 by someone running 334bhp@24 psi, according to his rollers, and 280 odd torque, was fast but f**k did it drink.
Later on emeralds rollers the truth revealed 280bhp 270 torque at 24 psi and 11.1 AFR, nearly so rich as off the scale.
It now runs 300bhp 297 torque on 17.5 psi, and up to 40 mpg on a run, runs like a dream and with 180,000+ on the clock.
I took opposite lock and his mate for a drive yesterday, just ask them, think they were impressed for a car with that mileage!!
tabetha