I always experience a bit of trepidation when considering the purchase of anything in .17HMR, but I'll likely break down this spring and buy a rifle in the caliber.
In your situation, you might want to research the velocities of the .17HMR from barrels more representative of the length of barrel the Striker possesses if you haven't already. Since the velocity seems to be the only advantage the .17HMR has over the .22WMR, it should seem to prove quite relevent in deciding between the two, IMO.
Though the .22WMR does have the significant advantage of ammunition selection, the gap appears to be closing as other ammunition manufactures are offering their own recipes to the public. However, I have no doubt the .22WMR will always have the decisive edge in this catagory.
If it were up to me, I would likely choose the .17HMR if the rifle-to-handgun velocity loss isn't too severe, as I've always been a sucker for variety.