If size of the workpieces isn't an issue, then yes, you are probably looking in the right place. For production milling of those listed alloys, you would need to look at quite a bit larger, heavier, and more expensive of unit. Engraving those alloys and cutting Delrin it is fine though.
It will go through the Delrin like it isn't there, as will almost any of the small mills. For the engraving, however, among all the inexpensive options the Taig has the high spindle speed for it and is the best suited among the choices. So for both of the jobs you list it is quite well suited, and they are actually quite tough - they hold up in production environments cutting things like Delrin frighteningly well, especially considering its cost.