I loved to see a Cuis version of SqueakJS. Just pare it down to its essential classes just to give developers a clean base to experiment with the language on. No e-Toys, no Metacello, etc.
Been there, done that. You need SqueakJS, a browser an the changes, source and image files for Cuis. Startup is a bit slow, but it works. SqueakJS is just another VM.
I should add that I only tried the 32bit images etc. (Cuis*-32.* files).
This. I went down this road for some time before I reached a point with Pharo where I feel comfortable doing things their way.