My suggestions, subject to correction and refinement:

#1: stenocereus thurberi
#2: stenocereus pruinosus
#3: cereus peruvianus montrose
#4: Cleistocactus strausii

Don't know enough to comment on #1 &2, but I agree with Para on what #3 & 4 might be.

Josiah,
1, 2, & 3 sound right, #2 is also known by Stenocereus victoriensis (pruinosus with more glaucous skin). Number 4 though might be Cleistocactus samaipatanus or a Haageocereus (close relative). C. strausii is very white and has more or less soft spines. Nice plants.
Dan

I am in agreement with Dan about #4. I thought the same before I read his post. The other 3 have been correctly IDed..
Bill in SC

I dpn't think #4 is C. strausii.

Not white enough for straussii, may be Haageocereus icosagonoides, or H laredensis.

CP

The only one I know is 3, Cereus peruvianus 'monstrose'
I used to have one.