I am probably ordering 4 x Toyo Proxies T1R's today.....
hope they will be ok, you never really know till they are on, and then its too late 
Shame you can try before you buy Jim. With that in mind i started a thread for reviewing tyres on the omega. I'm sure between us we must have tried every make. It didnt take off though.....people tired of the subject i guess. But i think its very important subject on these cars, they can drive very very differantly one set to another.
To answer, i think its safe to say do not buy falkens. Especially the 912 model. Very unstable.
I have conti sports contact 3 fitted. Very happy with straight line stability and grip wet and dry is excellent. A fraction noisier than falkens though, but only a fraction. Not cheap.
Will go for Dunlop next time though. Probably the most.....accurate.....planted.....stable tyres i've experienced on the Omega.(swapped wheels with other members on here) Bit noisy though, and also pricey.
Thats all i have on this subject. Except to say tyres are a funny choice for some people. Not everyone has the same taste and not all notice the same trait in a tyre. Indeed price above all else often seems highest on the list, and for me on this car, that seems to be the start of the problem, but thats just "my" experience.
Hth