As you have already been told, requests are generally made at the time we reserve, and are not guaranteed. Check with II and see how they do that part of the process. As for the "best" location.... That is all dependant to each persons preferences. In over 20+ stays at OKW, I rarely make a request other than non-smoking for medical reasons. I do have my favorite areas and buildings, but I have never been in a building I thought was not good in some way.
A lot of what you request will depend on the size unit, the number of folks traveling, and your preferences for view, location etc. If you are staying in a 1 bedroom and planning to have someone sleeping in the living room, then yes, you would want to request a building number 30 or higher, because it has an extra door to half of the bathroom via the laundry room. If it is essential that someone in your party can't negotiate a flight or two of stairs, then you would want to request an elevator building or a first floor unit, but be aware that ground floor units are often under Grand Villas and can be a bit noisey. My DH has bad knees, but even he thinks the stairs at OKW are very well done with gentle rises and are not an issue. No need to carry luggage, since you can have bell services do that for you. If you are one who likes a nice morning sunrise view or water view, you might request that type of thing, and there are plenty at OKW. The views are basically woods, water and golf course. I have actually only been in one building that had very little view, and that was building 29. It was very hemmed in with vegetation and very near a golf fairway (probably why it is hemmed in with vegetation). We never worry about being close to the Hospitality House, since the internal bus and ANY bus for that matter, stops there as it's last stop before leaving the resort. There are 3 other pools throughout the resort as well, and we actually prefer the South Point area. Generally, we say make 3 requests in order of preference. For most, smoking preference is the first request followed by location and view.
If you look at the map linked in the above post, you will see that the areas are listed by bus stop area. If I had to list my favorites, they would be buildings 55, 46, 21, and 13. I didn't care for 64 because it doesn't have its own parking lot. I also didn't care for buildng 29.