A good selection of travel trailers which are for sale can be found on many websites. These websites include "Craigslist" "RV Registry" and also "RV Trader Online".
This website has an excellent selection of Lightweight Travel Trailers: http://traveltrailerdeals.com/Travel-Trailers/lightweight-travel-trailers. If you are looking for a second hand one, Ebay and Craigslist are good venues.
Traileroutlet.com has a wide selection of all types of trailers. Also try trailersforless.com for a good selection of gooseneck flatbed trailers.
If you are looking for stores that have used cargo trailers for sale, take a look at Tucker's Trailers and RVs. They have a good and decent selection of cargo trailers that you can buy.
Ebay is actually a good source for finding concession trailers in your area.
Ebay does sell travel trailers. They can be found in the automotive section of the website. It is recommended to buy this from someone that has a good seller rating to decrease chances of buying something that isn't as advertised.
I would like to buy some cheap utility trailers. Where is a good place to look for cheap utility trailers in Canada?
There are many good websites that offer enclosed trailers for sale. They will be geared towards trailers for sale in various areas. Kijiji is a good website to find items for sale in a community of interest.
The best online site to order kayak trailers so you can have one for the Summer would be the following: http://www.sportsrig.com/. They have a good selection.
When buying used travel trailers you must make sure that everything is in good condition. Also, make sure it has not been involved in any accidents.
You can find a lot of indoor grills through sears.com. You can also search with amazon.com to find a great selection of indoor grills for your home or to travel with.
Big Tex Trailers and Trailers for Less offer good information about flatbed trailers. You should be able to get a good knowledge base from these websites.
Custom travel mugs can be found online from Amazon, they have lots of different styles and size, price of travel mugs to choose from. One might want to shop at Walmart as well.