Mesosilver, Utopia-Silver , and Sovereign Silver are all in your own words going to have "a strong marketing team that gets their product into many of the supplement outlets."
Just because Utopia-Silver is Curezone sponsored and you're buddies with the owner doesn't make the companies claims any more legitimate than Sovereign's unless there is 3rd party testing done with no financial interests.
Now most of what I've researched on Pubmed confirms that the Ionic portion is what is most effective. I know you'll agree with this as it is thought that Colloidal solutions convert to Ionic once it reaches the pathogen in the body.
I have yet to find a study which proves that Ionic Silver is less bioavailable than "true" Colloidal Silver .
Until then, I'll have to base my conclusions on what I have found effective from my own experience with what I make at home.