Wes, I think the simplest answer is just to purchase one from the Tamiya Reefer Trailers and just make any modifications that you want
With that being said, I spotted this trailer last month on Ebay and drooled
I just wished that I could have afforded to buy it for myself
I saved the link in case I decide to make an attempt to build a custom reefer unit on my dry-van
You can also view it here:
http://www.ebay.com/itm/CUSTOM-1-14-...vip=true&rt=nc
Good luck
- RCT