Sounds like you have three very good choices.
OKW: Great resort - lowest room points across the board, and best bargain on 3 bedroom grand villas - which you need OKW points to book...but...OKW only has 1 or 2 buildings that have elevators. Given the size of the resort dues should be in the lower tier of pricing and has historically been in the lower tier for the most part
SSR: Another great resort and I can't wait to see the refurbed rooms. It is a large resort like OKW, but has preferred and standard room categories, with preferred being the springs ( Carriage House location) and congress park (closest to disney springs. However standard view has great options of Grandstand, and Paddock Pool. Point wise preferred is similiar to the other 2042 resorts, but standard is close to OKW
point chart. Given the size of the resort dues should be in the lower tier of pricing and has historically been in the lower tier
RIV: the newest resort and another great resort. This resort gives you skyliner access to Epcot and HS, which is a plus. The room decor looks very nice online (have not stayed there yet). If you are not planning on selling then resale restrictions are not an issue, but no one knows what the future holds. I think there will be a line for the skyliner at certain times of day both leaving the resort and heading back due to the fact its final stop are the really large value resorts. Point chart wise, RIV charts are more than either SSR or OKW so your points will not go as far here. Dues are also high here and my fear are the dues that will go into maintenance of the skyliner since RIV has a stop there which is separate from the hotel side, then it is technically maintained by RIV dues.
All three are great resorts and you cannot go wrong with any of them.
in a nutshell here is my overall opinion:
OKW: Best value point chart of all resorts and largest rooms. Ability to walk to disney springs, but it is a bit of a walk - i think close to 1.5 miles
SSR: std view rooms are a great value and the ability to walk to Disney springs is another plus
RIV: newest resort, rooms look very elegant, but high point chart and uncertain future resale market
Regardless of which resort you purchase - and not sure how many points so this might be mute- I would recommend breaking down the points into 125 point contracts or less (if purchasing 200 buy two contracts 125 and 75 points; if 250 buy two contracts - 125 and 125. Just in case you ever decide to downsize you can and still maintain your member ship - i made sure one is 125 so if you downsize you still maintain your bluecard.