That is similar to a recipe I have been working on. I want to use 85% pilsner and 15% munich, but I am shooting for a lower abv - maybe around 4.5% or even lower. I am a little worried about the body of the beer being to thin so I think I will just mash really high - around 158F and hope for the best.
I am also considering a very light touch of honey in the fermenter and possibly a little spice addition at the end of the boil. Coriander or chamomile have come to mind. I am planning on using wy3522 Ardennes yeast on one half of the batch and 3422 Belgian Wheat on the other.
Yours is going to be quite hoppy with 3 oz of aromatic hops, and I am not sure I would like that as much. The idea for me is to let the yeast be in the lead, then the malt, and then the hops take a back seat. I like a hoppy saison, but I don't think t58 is really a saison yeast, is it?