If you buy direct from the Chinese, you aren't going to get much support, if any, especially if you are able to buy only one or two units. One or two units won't be direct from the manufacturer/factory, but from a middleman over there and the firmware isn't likely to be US.
The actual manufacturers/factories over there won't likely want to deal directly with you unless you're buying a large quantity, very often when they say minimum order of a thousand, or something like that, they'll cut it down to 500, 250, but not to just a few units, only a few units at low cost will be from a middleman with likely no support. The manufacturers/factories also only like dealing with companies, or if you look to be a company with a professional looking web site, contacts, etc.
Fees for customs depends on how it is shipped, best to look that up, it's been too long for me to know for sure.
If you're looking to run Kodi/XBMC, look into the Raspberry PI2. It does a good job of it if your internet connection is decent and it's cheap and small. I have a mini bluetooth keyboard hooked to mine and the PI2 strapped to the back of my TV.