You can also use the Techtom CMX-100n on 240s. I have one in my SE-R and in the 240. It is very small and only monitors MAF voltage, injector duty cycle (as a %), water temp and vehicle speed.
The beauty is it has peak recall available, so you can make a run and then see the peak value reached on whichever sensor you're monitoring while on the return road at the dragstrip. This is great for turbo cars to make sure you're not maxxing out either the MAF or injectors. The CMX is the only one with peak recall ability, too.
http://www.technosquareinc.com has the Techtom units.
As for the Consult boxes...I just acquired one of them and am running Consultan software (freeware). Pretty freaking cool, as you can see all the sensors in real time and log them. They even have the software for Mac OS X.