Almost any programable ECU is fine. I would be getting one that does ignition tho. The ign control is where a lot of the power, drivability and economy comes from.

Just find one that can use the crank and cam triggers you will be running. Also something with a harness plug and a wiring diagram.

Altho i like the Haltech ECU`s, the F7b is a dinasour. The F9 onwards(w ign cont.) would be better.

Megasquirt are another option if funds are tight. Often seen as cheap, they are more than capable and reliable using high end processors.