Carl is spot on..
As with the second hand side, the costumes to best avoid are mostly Stormtroopers, as they are generally built to the persons size & build. They are very hard, if not impossible to adapt to fit someone else. Always best to buy those in kit form.
Your height will determine what costume is best to go for. A 5ft Vader is a no go, and a 7ft Jawa looks silly. 501st UKG are pretty strict on the accuracy side of things. Best to sign up over on their forum, introduce yourself and PM (not post on forum) the armourers about sourcing the right costume for you. They will point you in the right direction.
Wanted - Instruction sheets and Stormtrooper cardbacks preferably....
Lili Ledy Boxed Speeder Bike
Survival Kit Mailer - Sealed baggie, open box