Where do my brake lights go

[purzell]

So I'm going to buy some lights to make my truck completely street legal. I want to buy the correct brake lights. I'm not sure if either of the ones back there are even right. See if you can tell from the photos and perhaps someone can tell me where the right ones go and what they should look like (or a similar part at a distributor.)

Thanks!

1966 GMC long stepside