Tobias Quintin - Choose this one! I love it... Tobias is the perfect mix of familiar yet unique to me, and it sounds great with Quintin. #1 choice.
Quintin Russell - Very nice name, my #2 choice.
Isaac Quintin or Isaac Tyson - I really like Isaac, but it's too popular for me. It also doesn't sound great with your MN options. #3 choice.
Tobias is my favourite