Any suggestions as to what cruise control to fit to a 1990 SW20 turbo?

not sure if i was factory stock, but my first MR2, ADM 91NA has cruise control fitted.
Reading Wiki it does mention that Japan stop using them on one of the updates. As i guess i'd say it does exists
 
Some one want to clarify?

Yep, one of our 1990 SW's has factory cruise control.

So where might I acquire one? Do you have any idea how it sensed speed?

There is a speed controller / speed ecu up under the dash on the passenger side.  Reads from the speedo, sends signal to the actuator in the engine bay.
 
Currently waiting on word from the insurance assessor on the fate of this SW . . .

My '90 model ADM has cruise, as well as other ADM cars I know of.
 
I would think there would be a long list of stuff needed to retrofit it.

Yes I think I would have to have a close look at my imported sw20 and see if it has the necessary gear to fit a second hand factory cruise control. I am dubious about the speed control as my sw20 speedo is cable driven. I was wondering about the after market units that use magnets on he drive shaft for speed sensing and a vacuum unit to pull the throttle. However I am unsure how the vacuum would work if their is positive  pressure at time in the manifold.

Our SW's are both cable driven, the cruise control computer gets a signal from the gauge panel itself, not the speedo cable.

So what and how is the throttle pulled on the factory set up?

mlee76
So what and how is the throttle pulled on the factory set up?

By an actuator located rear driver's side of the engine bay, and is cable interlinked to the throttle cable.
 
Parts location in the pic shows you just how much 'stuff ' you would need to make it work.
 
The top diagram shows for LHD cars. RHD is reversed.
The bottom diagram is the same for both.