Hey Jen,
For the trailer I used this harbor freight trailer: http://www.harborfreight.com/1195-lb-capacity-48-in-x-96-in-heavy-duty-folding-trailer-62648.html
The harbor freight trailer is probably the cheapest option you can find, but the quality of the trailer is not as good as the aluminum one that CLC had designed for the teardrop. I think the lifespan of the aluminum trailer would be far greater than the harbor freight trailer. Also, we did some modifications to the trailer to make it work better for us, mostly welding it all together so it would be stronger and shortening it by 10″.
As far as electric systems, I used solar to power it. I bought this solar panel kit and this deep cycle battery and a fantastic fan vent. I oversized the solar panel and battery, so you could probably get by with a smaller system if you wanted! Aside from those big things, there are a lot of little things you’ll need for the electrical system. Switches, fuses, wiring, whatever accessories you want, lights, etc.
Enjoy the project!