There is a simple formula that can be used when you are buying tyres, that is to buy the best tyres you can afford.
The slight advantage we have with the A2 is that the car is so light and does not have top cope with over 110mph and so the tyres are not on their limit.
If I was buying tyres for a BMW M3 for example, I would spend hundreds to get top quality tyres. The stress those tyres would take at high speeds and high cornering "G forces" is significant and chep tyres would be dangerous.
So as I say, buy the best you can afford, simples!!!
Steve B