I presume you mean T1R?
The toyos are about 5 years old in terms of tyre design. The F1 Assymetrics are brand new. I'd be looking at the F1 Assyms, or perhaps the new conti sport contact 5p.
NEVER put the better tyres on the front of the car. Might seem like a sparkling idea, but you can easily feel what the front end is doing, and can control it via the steering wheel, not so with the rear. Better tyres up front means your car feels nice and solid, with plenty of grip and steering feel, right up to the point when the **** tyres on the rear let go and put you backwards into a hedge.
Only just a few months ago a friend got bitten by this exact thing, even though he'd tried to apply my logic. One set of tyres were semi-decent contis, but were down to 2mm of tread, other pair were plastic povertyspec ditchfinders but had lots of tread. So he did the "right thing" and put the ditchfinders on the rear as they had more tread. First damp roundabout he spun the car and got ploughed into by an astra. Said there was no warning, steering felt normal etc. He then swapped them round and put the ditchfinders on the front just to compare, and the lack of grip was astounding, but at least with them on the front, he could feel it thru the steering. Needless to say they were all ditched and replaced with a fresh set of new rubber shortly after.
GSD2's are pretty old too, are they still in decent condition?