OK, here we go...
How many branches of Military does the Rebellion have? How many were represented on Hoth?
OK, as far as I can tell Paul, there's at most 2 branches of the Alliance Military, basically... But, it's also possible there's only one real military and that ground and "space" are combined.
Most assume there's an "Army" and a "Navy". Army takes care of combat on planets, Navy takes care of combat in the air/space, etc...
My opinion is though, that the "Fleet Command" is the only real branch of the military. That they're the basic combat unit of the Alliance. Branched off from them are the Special Forces, which I feel are an entity all their own and they encompass not only Special Forces soldier units but also Intelligence/covert ops, etc...
The "Fleet" Makes up the bulk of the fighting force. Liken them to Marines if you will... Some work aboard ships like the Tantive IV, Mon Remonda, Liberty or other vessel of the fleet... Some perhaps work in space stations, or on land bases. Either way, they're the main force. They would include pilots, Fleet Troopers (Front line soldiers, as well as crewmen/personnel), Technicians, and all the various levels of troopers/officers.
The Special Forces are a separate entity who work with the Fleet... They see combat maybe more routinely, and perform multiple tasks against the Empire as well, but they're strictly combat, espianoge, sabotage, etc... They would include everything from whole units of special forces like we see on Endor, or like the famed Rebel Infiltrators, or they would be limited to individual soldiers or "agents" like the well-known Kyle Katarn perhaps, or a spy undercover even.
These guys would have officers like Crix Madine, and his uniform... This also sorta covers the uniform difference, and it partly covers why Lando would be part of their little clique and automatically promoted to "General". He's technically not a "military" or front line officer... He's more in the CIA of the Alliance, sorta...
I have theorized that Spec. Forces would be so important the Alliance though, that they would be a separate branch unto themselves. An off-shoot entity of the main fighting force, the "Fleet", but the Fleet is the generic umbrella term that covers both Army and Navy...
I think it's entirely possible the Empire works in a similar fashion... There's not necessarily a distinction between Army/Navy. This would explain why there's little uniform distinction between their officers. It's more an Imperial "Military" than separate branches.
Also since we know George Lucas liked to make the SW Universe look "used", can anybody help me pin=point the actual stuff they used to make the Typical Front Line Hoth Rebel.
Well, I can say that the Rebel Footsoldier's blaster rifle on Hoth that we see them use the most (And on Endor) is a modified German MP-44 I believe it is...
Their goggles were simply ski goggles as well, but the rest of their uniforms were made especially for the film if I'm not mistaken.
The side-arms on the Hoth soldiers varried between the DL-44 style blasters of Han/Luke to the RFT style blaster we see on the Tantive IV and Death Star, and even some of Ponda Baba's type of blaster were used. MOst of the soldiers seemed to have a sidearm though, in addition to the rifle.
The rest of the get-up was pretty well hand-made as far as I know though.
On the Xwing uniform (and Y Wing Uniform in ANH), were the boots they are wearing more of a "Jack Boot" or more like a riding boot. In all the publicity stills and stuff that you see of Luke in his Xwing gear, he is wearing the Riding Style boot, like Han Solo Wears the whole trilogy.
I'd say it's likely that the boots were like you see in the production photo, though some shots of Luke's boots can be pretty clearly seen in the film as he ascends and descends the ladder to his X-Wing. So keep your eyes peeled on those images is my best advice.
And keep in mind on Luke's ONE leg he's wearing a band of cylinders similar to what many WW2 pilots wore, containing flares and survival gear and whatnot. So his boot may appear different on that leg, but I'm sure it's identical underneath to the other boot of course.