The first one could be used if you swapped the input nipple to a cga320 for CO2. The scale of the output gauge is a little high for our use but is still usable. A replacement gauge could be bought for about $10.00.
The second regulator is more idea with the scale of the secondary gauge and the fact that it already has a cga 320 nipple. But, I see a white residue around the relief valve. It makes me think the diaphraphm is blown. It could be rebuilt for about $50.00 at: http://www.regulatortorchrepair.com/
and it would be like brand new. It is also smaller and lighter than the first one. Judging buy the model number it is kind of old.
Oops, sorry, looking again at the picture of the second one, the white residue is on the output, not the relief valve. The second one could be a good buy. The output would probably be replaced anyway.