Check out Trailer Weights in the Real World
in the General Chat section. It's a database of actual loaded weights of various makes and models. Post #297 links to a spreadsheet that sorts, filters, and calculates averages.
Check out your intended tow vehicle's owner's manual for everything it says about towing.
Check out the 2016 Rally Map
("More" tab at the top has a link). A rally
is a great way to get a look at different molded fiberglass trailers in one place, since you won't find them at local RV dealers. Contact event hosts for advice on scheduling a visit.
Also in the "More" tab, look for the Document Center and download the Buyer's Checklist
. It will help you evaluate the condition of a used fiberglass trailer.
And, of course, check out the classified ads here
and at Molded Fiberglass Travel Trailers For Sale | Fiberglass RV's For Sale
Your budget should give you some options. A 16' is about as small as you can go to sleep 3 and have a small wet bath. If a second child might eventually be in the picture, you might want to anticipate that now. Some models only sleep three.
We camp with four people in a 13' bunk model (you can see pictures if you click the "Registry" link under my profile at the left). Since we stay at state parks and similar with facilities, a bathroom wasn't essential for us. Scamp
does make a 16' model with the same bed set-up, but more galley space and a small wet bath. It's a nice family layout.
Happy "egg" hunting!