I did my dissertation on tyre grip and did a fair bit of research into tyres in general.
I absolutely hate to see cheap rubber on a decent car, whats the point in having a car like the celica and then being let down by what connects you to the road.
I have no experience with any tyres you mentioned other than the Rain sports 2's, i was very happy with them in the dry and extremely happy in the wet. Great choice of tyre.
If you can afford to put them on over the cheaper rubber do it and dont look back you wont be dissapointed.