Where are you located?
country?
Province/state?
Have you tried your bass pro dealer?
I'm partial to Karavan trailers, designed and made well for most boats under 23' or so.
You're gonna need some measurements.
weight of fully loaded boat.
Width of boat .
Length.
length from transom to bow eye.
You looking for a bunk trailer, or a roller trailer?
Aluminum? Steel, galvanized or painted?
With or without brakes?
Could be anywhere from $1000 up to $3000