As Clive says - a bit of overkill. In theory it should work, and the argument that the UC300ETH (or whatever) will only draw the current that it requires is correct, however, big PSUs like this are sometimes less well regulated when substantially under utilised. Chances are that it will work, but something closer to the requirement of the UC300ETH (and any BOB, limit switch, relays, etc) would be sensible. 2A would be my target for something like this.