Disc lock is all the same a low protection. Those with alarm, as you write it, can be dissuasive and put to flight the thief. I shall go to see before the delivery of my motorcycle tomorrow.You could use a disc lock, there are ones that are alarmed so they make a racket and hopefully act as a deterrent. They are easily transported being quite small. If you are looking for security when you are at work (if you plan to commute on it) one of the best ways it a big chain secured to an immovable objet (lamp post or the like), you could leave it at your place of work where you will park it so you will only have to get it there once.
There is the alarm/tracker option, try to park it in the most secure places you can.