Yes dual staged system will get you much lower temps.
My current system that will be chilling my computer is a dual staged cascade system.
Although the cascade system does have a leak.Probably one of the flare fittings.But I am going to scrap that and go with a dual staged cascade cooler.
So that is 4 compressers altogether heh.

2 of em are 1/2hp and 3/4hp.The cascade compressors are 1/8hp and the other one I am not real sure of.Got it at a junkyard and no ratings on it anywhere.I am hoping it is bigger than the 1/8hp compressor.
It currently gets below -60F
I need a better thermometer though.

Also I dont think Kryotech gets -50C

Oh yeah I am not sure if having the same hp compressors as a dual staged system would work as good as having say, a 1/4 and 1/8hp.
You could also make a cascade system out of it.I know a killer way to cool the condenser of the first system