I always wanted one of those Baja bikes. But too little too late as they are no longer available. I liked that they actually had front suspension. As far as a motor upgrade on the Coleman? It already has the same 196cc engine the Baja Monsters came with. I rode it today, it has plenty of power. And if need be I have a bucket of old left over Kart racing parts that I can wring 12-13hp out of that engine.
I'm seriously thinking of getting one for myself. I may look around for a used Baja.