I think the figure looks pretty good! I have a TIE outfit so I'm a little more drawn to this than some, perhaps. I have a little bit of knowledge about the nuances in the uniform so I'll try to address a couple of the questions in the thread:
Besides colour, the jumpsuits are essentially the same throughout ANH: black for some Navy Troopers, Bridge Crew, Imperial Gunners and TIE pilots; grey for scanning crew and Rebel ground crew, blue for mechanical crew and orange for Rebel pilots. The only other real difference was that Rebels had an extra set of pockets near the boot (which are German jack boots--often with a side buckle). As far as I can tell, most pockets in ANH had rectangular flaps. During the filming of ESB and ROTJ, flight suits with chevron shaped pocket flaps supplanted many of the older ones from ANH. Both types of pockets were used throughout the latter two OT films.
There has been considerable debate about the differences between the TIE pilots in ANH and ROTJ. Complicating things is the fact that footage of TIE pilots shot in 1976 was used for ROTJ, as well. The 501st Legion's costume reference library maintains that ROTJ chest boxes had a third hose coming from the left lower quadrant of the chest box, while ANH lacked the third hose. Others argue for the opposite. It is argued that the rocker switches differed between films, as well. Certainly not all ROTJ TIE pilots had the third hose and there is no definitive proof that ANH Tie pilots had them or not as most shots were in-cockpit and primarily shot the shoulders and up. There's a photo of Andrew Ainsworth--the original vacuum former of the armour--mocking up an early version of the TIE gear with a third hose in 1976. Who knows how many of (or if) these made it into ANH? Perhaps they were only on the Hero TIEs, but never appeared on film?
This Sideshow figure has chevron-shaped pocket flaps more commonly associated with ROTJ. The rocker switches look more ROTJ, as well. It lacks the third hose, but not all ROTJ pilots had that--especially those assembled in the hanger when the Emperor arrives.
In my opinion, Sideshow was trying to emulate the details of the ROTJ TIE pilot in the visual dictionary:
Or this guy who was waiting for the Emperor: