If only we had the benefit of a long-rest, Orchid would have likely been the best 1 v 1 suitor. Alas, this will be challenging.

I assume Brannor will use a longsword. With armor and shield, an AC of 18 will be tough for a half-dragon to beat. If Greenest can offer any improvement on said armor (i.e. full plate) or shield (+1), this can place his AC between 19-21. 

We should also involve Mr. Lake in these discussions to see if anything, he can conjure for us. If the armor and shield is available but in poor condition, I wonder if Parum's mending can be of use.

Does Kyra have also Sanctuary and/or Shield of Faith?