I would like to close a gap between my front two teeth but want to limit the treatment to just two veneers. Is this possible?

It all depends on how much composite you have on the front teeth.  A conservative option would be to do whitening and just replace the bonding with a lighter shade.  Another option could be to consider a minimal prep veneer to cover the front of the tooth to get a more long lasting...

Hello,These stains on your teeth are mostly caused by excessive fluoride. Teeth whitening could make it worse. For a permanent solution, you might consider getting laminate veneers.

The space between the two is too large. The teeth to fill the space would make the teeth look very wide/chiclet like. I think a combination of Invisalign and bonding veneers would work.