I wonder are all these ISF calibration guy's equal.
No.
What should we look for or what question need to be asked?
Well, if it was me, and I'm sure it was anybody, How Much Does it Cost?
I would ask what specific gear they will use, (colorimeter, spectroradiometer, etc, and more importantly which models). Some tools are actually cheap (entry consumer), and some are thousands of dollars (pro), and there's a reason for that. Color is probably the trickiest part. What software, etc, how long it will take. How many possible calibrations are possible for my various sources, and is it even possible to make separate calibrations for each source for BOTH day and night viewing (like with a Pioneer Elite/Pro). How will this be reflected in the final cost.
In all honesty, I know I'd have almost zero luck, but if I could rope in a few friends to go in on some package calibration deal, maybe we could all benefit from a reduced price. I highly doubt I could convince my friends, but I only have a PJ, and am talking in hypothetical terms.
I've read over some of their qualifications and some appear to have more than others....

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IMO, the best way is to look for consumer feedback at forums. I didn't look up your town in CA, but there are people here who have received pro calibrations, and others who may not have, but live in CA as videophiles. Perhaps ask First Reflection if he has any recommendations for you in CA.
I did post this already for clouso's last thread on finding a calibrator, to which he never replied. Maybe you can benefit:
http://forums.audioholics.com/forums/showpost.php?p=635168&postcount=4
edit: Italicized text was copy/pasted from the calibrator's thread, in the calibration subforum, of AVS, after certain Canadian keyword search.