Bicycle Mechanics - Rear brakes on GT Timberline, what type are they?

So I've gotten most of my new parts delivered and started putting them on the bike just to discover the rear brakes won't go on. The original brakes on the GT were on the underside of the frame, by the chain, hanging upside down.
Are these types of brakes still manufactured?
Somebody help me out, I dont wanna be putting on the old brakes.

U-brakes, some BMX bikes still use them, so still available.

I gotta tell you that's a solid 9 or 10 degree of difficulty installation.

I'm thinking it will be quite a bit easier if you install and set up the brakes before you install your crankset.

Thanks.
Luckily the crank set is still not installed so I was able to put on the old brakes w/o problem. I'll have to get new brake pads and hope the setup works good.

The old brakes are Tektro and probably the originals - more than 10 years old. How bad are these and should I change them for a new set? They seem structurally fine with no visible cracks or deformation.

Thanks.
Luckily the crank set is still not installed so I was able to put on the old brakes w/o problem. I'll have to get new brake pads and hope the setup works good.

The old brakes are Tektro and probably the originals - more than 10 years old. How bad are these and should I change them for a new set? They seem structurally fine with no visible cracks or deformation.

They are probably going to work just as well as anything you can find new to replace them with.

They are probably going to work just as well as anything you can find new to replace them with.

That's what I think too.

They are probably going to work just as well as anything you can find new to replace them with.

And they are rear brakes, most of your braking power comes from the front.

Cool stuff... I guess I could've just ordered front brakes then...
Anybody need rear brakes? Brand new! :D