could I install an run Mango on this Linux device Dragino: http://www.dragino.com/ ?
From a quick look I'd say probably not. I don't think OpenWRT supports a JAVA JDK. I also couldn't see the system specs buy my ques is it is way under powered for Mango. There are other options for small embedded devices but I would recommend a minimum of 512 MB Ram, several gigs of Hard-drive space and the fastest ARM processor your budget can handle. The new release of Mango Automation 2.0.6 has been optimized to run on small embedded computers and there will be more optimizations coming in the future.