No villas at OKW can really "see" Illuminations. Quite a few will have a glimpse of the highest fireworks at the beginning and end of the program and you will "hear" the sounds of many of the displays, but none of the music or narration. I would not worry about finding a location just to "see" Illuminations, but if your villa has one it's a plus.
The closest buidlings to Epcot are 19,20,21 and 22, but one of those have balconies that look out at the fireworks. Likely the best with a view in that direction are 16, 62, 23, 24, 25, 27, 28, 29, 30, 31, 32, 38, 39, 40, 41, 47, 48, 49.
Not all villas in these buildings will be able to see the fireworkd and even if they can, the program lasts only a few minutes and it's easy to miss the view even though you will still hear the sound/noise. I would NOT make a big issue out of room requests based on the Illuminations fireworks. If that is an important component of your trip, better plan to be at Epcot - the view, music, narration and overall effect is much better in person!
