Umm, the compressed length of your springs doesn't change the height of the lower spring perch dude.
The Gram Lights will fit onto any OEM strut you can put on your car, including inverted STi struts. Same with other wheels I've heard you mention, and with your Rotas. And if you can hold out until you are done autocrossing, you might as well just put stock springs on, or maybe STi takeoffs. Softer is better in winter.