Just my 2 cents, but from being a owner of many trailers in my life ..I would get a bigger trailer than just minimum..It will not cost that much more to get a 6X7 or 5x7 trailer over the 4X6. Hell even Northern has decent trailers that you can assemble yourself. ( just put tires & wheels on ) and go pretty cheap..or better yet buy a nice used small trailer people are always upgrading to larger trailers..
be sure to look around i just bought a trailer off craigslist for 800 its a "deck above the wheels flatbed" that can hold 6 quads its 21 by 8 actual deck size. alot of the brand new small trailers run 500 to 800 bucks. so to sum it up my advice is go used go cheap just check out the frame and axels and so on first