Jeff,
My Dad and I have a 14' fiberglass canoe. He bought it when I was a kid and we used it fishing and for just floating down the creeks and rivers. It was fun and I still plan on using it, but it is very heavy. They may be made better and thus lighter now, I am not sure, but if you go for fiberglass I'd be realy cautious about the weight.
One other thing that I have had, is a small 2 man plastic bass boat. It had 2 swivel seats, the seats came out very easily so you can make it a 1 man with no problem. They were very easy to fish from although I was not fly fishing, just regular fishing I am not sure how well they would work for 2 men fly fishing. There was room for a battery and trolling motor, I don't think it would be the easiest thing in the world to paddle, fortunately, I didn't have to. At the time I got mine they were about $300, so I would think they would be well with in your price range. It was filled with foam too, so you couldn't sink it if you tried but loading it was a breeze. May not be what you are looking for, but its a thought. I can't remember the name of it though, or you could just google a look at it.
Hope that helps,
Jason
"If we lie to the government, it's called a felony, when they lie to us, it's called politics." Bill Murray