I would love to be in your situation with two qualified tenants to consider. I believe you should go with the first qualified tenant if all other things are equal. In other words if I had two applications for a rental and the two were both good qualified potential tenants I would take the one that turned in their application first.
My thought process on this is based on a presentation years ago from an Equal Opportunity presentation to a landlord group that I attended. This was in regards to housing discrimination and potential fines but at that time there was also some discussion on discrimination of folks with children, sinigle mothers, age, along with the more prominent issues on discrimination.
Best of luck and congrats again on having more than one potential tenant to consider.
To answer your question as to whether I agree with your decision would take a little more background information but like I said sounds like you are in a good position either way.