If I get an SH Forester or an 08-11 5-seat Tribeca... it will get new wheels and tires, and a modest profile that is not bulbous, nor low-profile electrical tape wrap on the wheels... Probably 17 or 18 on a Forester, 18 likely or 19 at most on a Tribeca.
It will get a wheel design that isn't ridiculous, isn't dowdy, but isn't spider-web thin sports-car wheels, either. I'd like to hope that I can find a nice set of *forged* aluminum wheels. meaty SUV-suitable 5, 6, or 7 spoke. Maybe BBS-CH or RE style... if they would look just right.
The tires will not be stretched... conversely, they will be substantially WIDER than the wheel rim, and protect the wheel. Widest tire tread with that is rated to fit on the wheel rim width... the wheel rim and tire width will be closer to 9" wide than 7" wide, and offset to fill the depth of the wheel wells, without sticking out of them.
With a little bit of additional rolling diameter, it might actually lower cruising RPMs a tad bit, which is good for distance highway mileage.
It will also fill out the fenders better, height wise.
With that wheel and tire I am not sure it will need to be lowered. But maybe a very slight lowering (an inch at most perhaps) on the front, to rake the vehicle just a little bit to look less dowdy than stock and not have a saggy-butt stance, but not really to impact ground clearance effectiveness much.
Which Forester I choose to consider will depend on the 2014 specifications... and so far, aesthetics, and inference of what the drivetrain is likely to be... it will probably be an FB25-powered SH, instead.
I would consider the XV Crosstrek if it gets a performance model, such as a turbo engine and a stick shift together, like a proper rally car... but until then, no consideration.
It would be easier to raise the suspension of a GR STI hatchback than to put a whole performance drivetrain under an XV crosstrek after it has already been manufactured and sold.