Mr Bill, if you retro a normal resi evap with 2 txv's then you have to cut and braze the coil circuiting. That is generally a dicey proposition. I did it on a 40 ton system at a Catholic church on Long Island, NY and it worked perfectly. Seen it a million times in commercial refrigeration apps but not in resi. But then again you did say it was specialized.
Would love to talk sometime! I'm sure you could teach me.
To the guys that post here, yes, I knew that changing a condenser can't possibly change anything about indoor airflow but that seemed to be the premise of some of the responses and I may have mis-understood the answers.
To answer the question to InspectorG, it can be done but highly unadvisible and I wouldn't put my P.E. stamp on it.