Been looking over Nev & Pan’s questions and ideas for the clone plot in AotC. Wouldn’t the simpler solution be to go with the idea that the clones were originally created for the Separatists, and that the Jedi basically claimed them for their own? Have one of the alien Separatists dialogue say “when will you finalize the Kaminoan deal?” And Dooku will respond with “I am a man of my word.” Then, after Palpatine is given emergency powers, change Yoda’s line to "Visit I will the cloners on Kamino…and barter for their army. If I’m missing any steps, let me know.
That is my preferred alternate version of events. The council seems much less stupid in this scenario, it still cast a mighty shadow on the Jedi for betraying their ideals like that, and it even adds to Dexter‘s line which characterises the Kaminoans as greedy entrepreneurs devoid of any moral commitment.
However, one point that would still need some work to really sell the change, would be Obi-Wan‘s visit on Kamino. The Kaminoans cannot be already working for the republic. Maybe the best way to keep most of the dialogue as is, would be to add a line from Yoda or Windu that explains that Sifo-Dyas was travelling with Dooku before he vanished. And while we‘re at it, maybe change Jango‘s dialogue to: „… a Jedi called Tyrannus…“. This gives Obi enough information to piece together what happened.
I also like your idea to reutilize Dooku‘s line in this context, I hadn’t thought of that. The only real connection point that I had in mind was the scene in Palpatine’s office. (Just make the alien senator say something, heck, maybe he could imply that the Kaminoans approached the republic after Obi-Wan‘s visit to make them look extra slimy)