After my failed trailer purchase last year, I decided to just spend the money.
I found a local welder to build me a trailer to my spec. It's 12' x 7' with a long tongue, 3500# easy lube dexter axle. I had him weld the frame and then I painted and wired it and put the deck on. I have a roller and winch parts sitting in the garage to install this spring.
The 3x3 HSS center member / tongue allows for attachment of a spare under the trailer right near the axle... out of sight and good spot for weight balance.
I currently have 14" wheels on it because I found a deal on some nice allow wheels, but it will fit 15s if I want to do that in the future.
It weighed 330kg (750 pounds) before I added wiring and the deck so I think it's probably about 1100 pounds in it's current state, but I haven't weighed it since that work was done.
Forgot to mention that it's designed to tow the boat we ordered last fall... an NRS E-176D... 17'5" x 7'9".