Hondata

I have a pr3 ecu that was running s200 I since then changed my cams and added nitrous to it, I took it in to have it re-tuned and the shop told me they don't deal with s200 anymore just in case somr thing happens they can't get another or parts.
My question is can I buy an s100 and just pop in the chip to the white four prong tab in the ecu? and have it work well?

Yes an s100 will work, but it still must be tuned using an s200. Any Hondata dealer should still be able to tune an s100 or s200. If they are telling you they can't we need to know who it is so we can discuss this with them or stop selling to them.