I am an multi-instrumental musician and I want to add cello to that collection. What is you guys's opinion on the Vienn Strings Frankfurt cello

I don't know the particular 'cello, but be aware that the most critical individual component for the sound is the belly, which is laminated on the Frankfurt. This could give consistency and robustness, but most likely at the expense of ultimate playng quality.

You might consider borrowing a 'cello initially; regardless, the most important thing is to find a good teacher, and choose your first "own 'cello" together - preferably after you have been playing for a while.