I would be slightly inclined towards the hyper 8. That said I own a hyper 7 and I think its a fantastic buggy. Its very durable, cheap and plentiful spares. It has stood up to over a years worth of abuse and unless you look at the bottom of the chassis you wouldn't know it. It even has the original A-arms!
A word on 'pro' spec buggies. Definatley try and go this route. Both the hyper 7 and 8 pro versions come with so much better quality components than the RTRs. I can go into the differences if you wish but just take my word for it, if you race you will save loads of money just getting a pro kit in the first place.
You will be pleased with either though I think the hyper 8 would be my choice if I was buying now.