Ivan feels like the name writers go to when they think "we need a minor Slavic character, most probably involved in organised crime". Bonus points if the character in question is from a country where the name Ivan is not used, and he speaks in a thick Russian accent despite not being Russian.
I don't know why, but I really dislike Ivo. It feels whiney and has none of the elegance of Yves.
Ivor is my favourite of these, as it reminds me of ivory and I like its etymology. I do think it sounds too similar to ajvar, though.
Hmmm... let's go with Ivan Vasilievich, Ivo Vasile, and Ivor Basil.
masculine list:
https://www.behindthename.com/pnl/191050/124079feminine list:
https://www.behindthename.com/pnl/191050/124080