I have the Harley hand controls on my chopper,
Yes they can be wired to a Triumph, (but a lot of stuffing around)
You'll also need to buy a self cancellor for the new system also, which will need to be wired in (more headaches)as the Harleys don't self cancel without there own prewired cancellor.
You'll need to run a lot of new wires also, so unless your good at wiring, or have a mate that is, I wouldn't suggest it, unless your going to get a full custom wiring harness.