the cover on the back of the clocks is from a faired one, and so are the clip-ons. And the headlight is not original (should be bigger - hens teeth by now).
the first is the ESD Blubber refers to, the second is the bike generally called "EFE", the 1135cc one, which I would go for if I had to choose.
Looks like the EFE originally had a fairing which has been removed at some point.
if both bikes are from 1985, the only difference is the fairing. Half on the ES, full on the EF.
Price depends on many things, especially on a 35 year old bike, so it's impossible to say which is the best deal from behind a computer screen.
750 L and M forks are the same as far as the parts diagrams show
https://www.motorcyclespareparts.eu/en/suzuki-parts/1990-gsx-r750-motorcycles/front-damper
https://www.motorcyclespareparts.eu/en/suzuki-parts/1991-gsx-r750-motorcycles/front-damper
they are different, but should work when swapped.
K has connectors for switchgear and headlights behind the headlights, M has those plugs just above the oil cooler in the side of the fairing. K also has headlight relays which the M does not have. 1100 has fuel level sender, 750 doesn't. And probably a few more small differences.