Sounds to me like you need a few bows, not one -- bummer
Ren fairs -- haven't been to one but is this just for display (costume) or are there shooting competitions as well? Hunting bow or English Longbow (war-bow)? What's your character role -- woods hunter or part of the king's army?
For demo purposes & a little small game, 40# is probably more than you need. Apologies -- can you clarify if you are an entry-level shooter or if you are a seasoned veteran with a bow?
Hickory-backed cherry sounds like a good combo performance-wise. I think ELBs were D-shaped -- different from a flatbow (American, I think). But I'll let others say for sure as I only have a little bit of knowledge here.
If the arrow pass is much past about 1.25" in width (5/8" from center), getting arrows to tune well becomes difficult for me. That could just be me, though. When I have wide handles, shot right-handed, my arrows still impact way left. Going to even rediculously low-spined arrows, shot bareshaft, still impact left even if the shaft lands sideways with the nock going left. Again, might just be me. But it has always worked better for me to just scrape the pass down a little more to reduce the width in that area. At least then I can get the arrow to shoot straight where I'm looking. For costume, none of this matters in the least. But for small game hunting, you're going to need some good accuracy & consistency. A little forgiveness is helpful, too.
You might want to post this question on the bowyer's bench forum. Very knowledgeable folks over there in just about any bowyer style you can imagine.