You are in a tough spot, but very similar to where I was earlier in the year. Pros and Cons of all IMHO
Tiller: Roomy, great floor space
Cons: Sore arm, poor visibility, cold
Single counsel: Better for long runs, Less floor space, more comfortable
Cons: passenger comfort, cold often narrower boats
Full Windshield: Comfort and happy wife
Cons: Floor space
To me it is a no brainer to get a full windshield. In the future I have no doubts I will go back to a single or a tiller, but the full windshield has many advantages that outweigh the negatives. The kids love it and so does the wife.
As far as being able to find a boat in your price range, I will wish you good luck. If you find what you want, be prepared to buy it immediately as they do not stick around long. Walk in the door with cash in your hand and be ready to make a quick decision. Good deals do not stick around long. Every boat will have positives and negatives. Get as many high priorities as you can, and let some lower ones go.
Good luck. Boat hunting is fun, but can be a killer at times.