If you are considering a trailer, you need to keep several things in mind. What ae you going to haul, how much will everything weigh, how far arre you going to travel with it and what are you going to pull it with? Your will find that a 16 ft trailer really isn't worth it, so if your business grows where are you going to put whatever you want to haul in 6 months? Don't purchase anything less than an 18 ft. I personally have a 20 ft and it works great. I can load my skid steer on it and take along any addition accessories I may need and still have room.
If your going to haul a skid steer anytime, make sure you have ramps that fold down with supports under them so when you load it you don't raise the whole back of you pulling vehicle off the ground. Your axles usually on lighter tandem trailers are 3,500 pound capacity, 5,000 are optional. Again what do you want to haul? You will also find that the longer the trailer the easier it is to pull, you don't get that baby-buggy bounce on every dip or bump. Another thing to remember is what is the height of you pulling vehicle. I have a super-crew so I need to use a 5 or 6 inch drop receiver hitch so my pickup is not going uphill all of the time but pulling level.
Just some suggestions from an old farmer!