any future major upgrade on link ecu?

It depends on exactly what you need.  If the G3 ECU's meet your requirements then there will be no advantage in holding out for a new one.  It is like anything, you will hold out for the next ECU, buy it then a better one will come along anyway.  It depends on what your time frame is.  If you are planning on buying something this year, then buy a G3.  G3 firmware will continue to be supported and upgraded as always.  We are continuously developing so new products are inevitable and eventually a G4 range will surface.

Which Link ECU were you looking at and for what application.  If you tell me exactly what you are doing, what engine you are running, what you need to wire and your time frame, I can help you determine the best ECU...

I don't know anything about the Pontiac, but our ECU's are not vehicle specific, the user configures them for a particular application.  In some cases we don't have engine position sensor decoding information for engines, so I would need to know a bit more about that car.  But you can use the same ECU for two cars just by downloading a configuration file into it.

We can do a plug-in option for the MR2 using an LEM G3.  We would need to know if it is a revision 1 or revision 2/3 car.  If you want to do a bit of motor sport, want full sequential injection or want to use knock control then the LinkPlus G3 would be a better option but is more expensive and requires wiring to install it.

The LEM can run 8 coils, but you pair them up and run them as wasted spark.  I always recommend a LPG3 for V8's anyway...  You will need to find out if the Pontaic has an LS1, LS2 or LS7 engine.  Also find out if it has electronic throttle.

LS2 is not a problem, we sell heaps of ECU's for them.  Best ECU for that is a LinkPlus G3 although the LEM G3 will run it.  We don't have a solution for the DBW at the moment, but it will not be long before we do...

wher abouts are you i have just finished a mr2 g3 lem install with great results the easy install plug and play made it a one day excercise to in stall and tune on my dynapack hub dyno