What to look for when buying shocks

So I found this in an old jeep catalog and thought I would share.
Yes it is a long post
Shock types explained: The two basic types of shock absorbers
are gas charged and hydraulic. Both contain hydraulic oil but
gas charged shocks are also filled with nitrogen that ranges
from anywhere from 80-360 psi or more. Gas pressure is what
keeps the shock oil from “foaming up” w/ bubbles. Nitrogen
gas forces the oil molecules to stay together preventing
foaming. “Shock fade” from foaming reduces performance.
Gas shocks tend to be more responsive and better suited for
High performance demands but cost more. Hydraulic shocks
are very similar to gas charged units in construction but do
not feature pressurized gas and are more economical. Hydraulics
tend to be less prone to failure and are well suited for slow off-
road use. Highway performance may lack in hydraulic shocks
but they do handle ruts and pot holes better than some gas
shocks.
Piston Rod and Piston Diameter: The simple rule of thumb
is that bigger is better. Big pistons have more shock
dampening capabilities while larger diameter rods are
simply stronger. Both features usually add cost to the
shocks price.
Shock body construction: Twin tube shocks feature the basic
shock body design and are the most economical. Twin
tube designs are commonly used for hydraulic, cellular and low
pressure gas applications. Twin tube shocks can still function
if the outer tube gets dented. Mono tube shocks use a thick
single-wall shock tube to enclose the piston, oil and pressurized
gas. Mono tube shocks can be more precise at dampening since
they can be made to more precise specs and tend to be stronger
than twin-tube shocks. Mono tubes are usually more resilient
to shock fade and have better heat dissipation and typically use
larger diameter pistons. Mono tubes tend to be more expensive
than dual tube. Contrary to popular belief, external reservoir
shocks do not have reservoirs to hold extra oil. The design
actually allows extra air space during the compression
cycle. Remote reservoir shocks tend to be the most expensive.


Two most common shocks- OME and Bilstein 5100s
OME -18mm piston rod diameter, 35mm piston diameter
twin, tube gas charged
5100s-, 14mm piston rod diameter, 46 mm piston diameter
gas charged mono tube