I agree that wood will require more maintenance. I opted for wood (redwood) anyway purely based on visual appeal in our garden. I've been very happy with it, but it does require a weekend each year to re-treat the wood. (I'm pretty slow). I'm in Hot Atlanta and the summers are very hard on bleaching the wood if I don't treat it. You may not need to do that in your neck of the woods.

If you decide on wood, I can highly recommend Sturdi-Built which is right outside your town there. (If fact, I flew out there to visit their place before I purchased mine).

As far as using glass: I decided on all glass. The reason for my decision is that I absolutely enjoy working inside my greenhouse and being able to look out into the surrounding garden. When the shade cloth goes on, you don't even know it's there.

But, you will definitely find out how easily the sun will burn your plants with glass, even on a cool spring day. When I remove shade cloth in the fall I need to be especially careful to place plants where they will not get burned. If I had it to do over again I would still use glass on the sides but a poly material to diffuse light on the roof (which is exactly what Sturdi-Built recommended I do).

Hope that helps.