James,
I'm sorry to say this, but it will be EXTREMELY difficult, especially if you plan to pay Itaewon prices, and in such a short period of time. Korean tailors have no experience making morning suits, and best case scenario, even if you show them pictures, exact measurements, etc., the exact "cut" of the suit will not be what you will be expecting, especially assuming that you would prefer an English silhouette. Also, the basting material that Korean tailors use is very cheap, and they dont pay attention to the construction of the canvas as much as they should, which is a shame. Arm holes are never cut right, and just that great feel of the suit wrapping your body is always off.
Personally, if I had no choice based on time constraints, and you really want to get a MTM done in Korea, I would ATTEMPT to visit either SEGI tailor, Lansmere, and/or a new tailor boutique called Mono Gallery (the reason I list Mono is that they actually know stuff on textiles and canvas materials.) , all of them in Chungdam. Maybe Sartoria Min in Coex. Be expected to pay a premium more than expected, and also bare in mind that these "tailors" attempt to cut very close to the Neopolitan fashion. I dont know how that will work with Morning Attire, but just thinking about the Eton / Godfather / Kimchi fusion just sounds horrible.
I think the best bet is search on Ebay UK to see if you can find a second hand Savile Row if you are lucky, or just go off the rack, OR rent one when you get to the UK. If its over 1 Million KRW, its just not worth it. Due to the amount of fabric and the labor, I would expect that they would hustle you to approx. that price range BEST case scenario, with sandpaper fabric.
Hope this helps.
Edited by koreaderivative - 3/8/12 at 12:27am