If you can stretch it's got to be the Losi.
I have 2 hypers, and have done my very best to smash them to pieces, but they just keep coming back for more, so if you can't get the losi, go for the Tq2 with the 21 engine. Don't go near the 28!!!!
Also, as per someone elses comment, you can't compare the 8T to a buggy. The 8 t is a tough truggy, but they all have longer arms, more weight etc, and will naturally suffer more if beaten hard.
If you break something on the losi, it will cost more to replace than on a hyper, but not to the point of being a real problem.
The benefits of the losi over the hyper are:
The engine is much better
The Shock towers & chassis bracing is better
The shocks are better - I hate the ones with spacers as opposed to threaded bodies
You get a decent transmitter that can handle multiple vehicles if your fleet grows
You get a starter box
Better Tyres - I always find standard hyper tyres last about a week
The Diffs are filled with silicone, whereas the Hypers tend to just have a bit of grease in them
You even get a decent RX battery
Haven written all that, it makes the Hyper look a bit rubbish, which it definately isn't, but I think that Losi, with everything it comes with is unbelievable value, and now I really want to buy one.