I started with a 6x10 for a 2 wheeler. It was an enclosed v-nose, heavy duty ramp door with a beaver tail flap. I installed a Condor chock & e-trac. This worked great for the 2 wheeler. I used it for the Tri but it was very tight for me inside for tying down. Also the ramp door cables are the narrowest part and there was only about 1.5" on each side between the cables and the trike fenders. I put beveled 2x3s screwed to the ramp & floor as tire guides. Also split pool noodles and put them over the cables just in case.
Traded that trailer last year for a 7x12 compund v- nose, with hd ramp door with beaver tail flap, single torsion axle & dove tail. I put in my Condor & e-trac. I do not use the clam part of the Condor (too hard for me to pull out and afraid I might wreck the revers), I use 2 ratchet straps through the front wheel into e-tac pulling forward from the Condor.
The extra width on this trailer makes it much easier for me to load/unload. This trailer also has electric brakes.
I tie the rear down with 2 ratchet straps crossed over from the axle rings to e-trac pulling forward. I also put a ratchet strap from an eye bolt out side each rear wheel, through the wheel to e-trac pulling rearward. Probably over kill on the straps but that is just me, trike does not move and there is nothing pulling on the suspension at all. I used sheepskin tubes where the straps go through the wheels.
I upgraded the stock trailer tires to the next wt range up Goodyears. Hung e-trac on the walls & front for spare tire, jacks & other trailer stuff. The whole thing weighs in at just under 3500# loaded with about 390 - 400# on the tongue. I pull this with an F150.
Sorry for the long response, hope it helps & good luck.