Not to confuse anymore but we looked at the option of driving on the trailer without any attachment on the machine at all so that directed us to a drop deck trailer with a beavertail. Would you be carrying any pallets or pallet like materials now or in the future? Perhaps a deck-over/beavertail would be better suited. We also looked into a tow charger. This unit trickle charges the break away battery when it is plugged into a pull unit, keeping that battery charged in case of a break-away. No brainer for $30.
If you are looking at new, some of these options mentioned are not all that expensive and may be cheaper from the factory than your time spent. LED lights are cool and may be a thing of the future. One consideration is the availabity of replacements. I have not looked into that yet.
The only other length consideration not mentioned is how much room you have to park at your job sites. We are looking at incresed size and may add 7 feet to our length. When added to the tow unit, in some cases, the distance between drives will not allow for both to be connected in tight residential areas.
Couple other things to look at are closed wheel wells (drop decks). Less road dirt/grime on the deck of the trailer and equipment. Tire ratings-some tires barely meet weights and some over design the tires from model to model. 6 bolt rims vs. 8 bolt rims-all in the trailer engineering and weight ratings. Jacks- definitely upgrade the jack to a 12k or more if needed. This will last longer, take more abuse and when wheels chocked, can allow you to load the trailer without the tow unit attached. Fully enclosed wiring in harnesses will help with maintence issues. Spring assist ramps are nice on the back. Extra tie downs for sure for who know what in the future.
We are looking at Towmaster/BigTow for our choice. We had a Trail King, but they don't make a drop deck size between 12K and 18K (something a local dealer is going to discuss with the factory rep). Towmaster/Big Tow are built very similar. These have the Torflex axels which have been very good for us (not a problem in over 5 years). The trailer rides just as smooth loaded or unloaded.
The "get what you pay for" is all in play here. A few might cost a little more now but if maintained well, they will more than pay for themselves and make up the difference in a short time. Just try to plan ahead. Who knew a trailer could be so complicated?