With your size, it might be wise to get fabric material of the proper shade and fabricate it yourself. At least you know it will fit you!
In a lot of circles that I frequent, it is said that the coverall patter was pretty much the same or the Rebel and Imperial pilots, Bossk, Imperial technicians and so forth. So, if you can find good, solid reference pics of the coveralls, replicating shouldn't be too terribly bad.
For the helmet, there is a local guy who may be able to hook you up. I'll send you a PM, shortly.
- Bill