Fit of the ESF depends on your neck:chest ratio. I am a normal BMI guy with a larger neck (16.5") for my chest (40") and the 16.5 ESF fits like trim MTM.
If they are too loose on you and you never wear a tie, you could try a smaller...
For codes, sign up for the Dealflyer. It appears you get better offers after you've been a customer for a while, but who knows if that is true.
There are sometimes codes on the back of the mailings they send.
Codes are mostly one-time...
chinos, white shirt with darker stripe/pattern, say navy check, dark brown shoes, maybe suede, with dark brown belt
the chinos have to be as trim as the jacket
I'd buy the one in a store, where I could try it on in bright light with 3-way mirrors, where tailoring would be easy and guaranteed (i.e., they screw it up, they fix it or refund you).
If you trust your local alterations person to do a...