Sideshow's Rebel Fleet Trooper is based on the first guy on the left of the picture above, who has been revealed to be Lieutenant Pello Scrambas. The Rebel Alliance troops were rather individualistic and much more rag-tag when compared with the white, ceramic-like, space-armored stormtroopers of the Galactic Empire.
Authentic likeness of Lieutenant Pello Scrambas
Lieutenant Pello Scrambas wears basic fleet shirt, pants with belt and boots (boots are nicely sculpted)
Rebel Fleet Trooper's gear - vest, helmet with antenna, gun belt with holster and DH-17 Rebel Blaster (obviously no match for the fully armored Imperial Stormtroopers)
Kubrick Star Wars Rebel Fleet Trooper
Anxiously waiting for Sideshow's Star Wars Imperial Stormtrooper (first previewed here) - a cheaper alternative to the more expensive Medicom puny Stormtrooper. IMHO Marmit's Stormtrooper is still the best 1/6 realization out there (Marmit vs Medicom Stormtrooper posted here), until I get my hands on the Sideshow version.
There's also my post of Darth Vader with Stormtroopers and my favorite: 1/6 Darth Vader and the Bounty Hunters onboard the Executor in "Star Wars Episode V: The Empire Strikes Back"