Certainly a possibility, and thematically fitting - the shadar-kai for the black (caped?) appearance, and the gnome can easily be envisioned as the tinker kind that gets all those utility devices to work.
In terms of powers, the Shadar-kai is close to the Eladrin, although I prefer the latter's longer teleportation range. The gnome's ability is unfortunately only reactive, although I suspect WOTC will eventually print a feat that changes that. Of course, both have an int bonus as an additional perk.