I would recommend that you look at the various pieces of the equipment separately.
Ex: buy the trailer separately, based upon it's appeal to you.
Go to a kart shop near you and ask the owner to assist you in your search.
AND....best wishes and good luck to you in your karting experience.
OH....make sure you know the class you wish to run it.....real fast, like Unlimiteds....great fun but
takes a good bit of experience to be successful there.