My dad baught a 97 z-71 4x4 extended cab 5.7l brand new, hes got around 140k miles on it now. They are basically in town miles. I think the only thing hes ever replaced on it is the battery and a fuel pump. Thats not too bad considering what its been through. He only changes the oil about every 8-10k miles(he runs synthetic). I can only hope my vehicles are this reliable.
Oh and yeah the GMC's do look better.
And I would also deff. consider buying used if you can find what you want. I baught a 2-1/2 year old 99 camaro ss that stickered for $31k for $21k. It only had 7k miles on it