^^^Most on here would say that the 225/45-16 star specs are WAY TOO wide for a 7" wide wheel, and being that the Star Specs tend to run the absolute WIDEST of most any street tire (200 tread wear+) in thread width, in ANY of the sizes Dunlop offers, they may be correct.
IF Dunlop made that tire in a 215/45-16 it would most likely have a substantially wider tread width than both the 615K (which run a little narrow on tread width), and the Rival S (which runs a hair narrower yet than the Falkens, but are also 2 lbs. lighter than the Falkens).
Many seem to think that the Rival S is MUCH stickier in compound than both the Star Spec, and the 615ks, and subsequently will probably wear much quicker than both of those tires, especially in the heat.
I was going to do the same exact setup as you are contemplating (even down to using the 225/45-16 Star Specs), but I wanted the wheel width to match the tread width, so I went with the 17x8 1.2s, and am planning on putting the 215/40-17 Star Specs on them instead, and YES, I am giving up some un-sprung/rotational weight savings to get the 'look' I want for the STREET.
IF I ever get dedicated pure track wheels, I will buy the lightest, widest 16" rollers that will fit, and that I can afford at the time.