From what I could find there are 3 different Kitchen Sink sundae variations sold at WDW:
1. The big one at Beaches and Cream which has 5 scoops and a whole lot of other stuff for $28.99. Served on a steel platter.
2. The mini one in MK which has 3 scoops (vanilla, chocolate, strawberry) and various toppings for $22.99. Served in souvenir Mickey pants.
3. The mini one at B&C which is similar to the one at MK but with additional toppings, brownie, and Oreos for the same $22.99 price. Served in souvenir Mickey pants.
At DCA, the triple scoop sundaes at Clarabelle's come in 5 varieties: chocolate chip cookie w/hot fudge, strawberry, mint chocolate chip, mocha almond fudge, and "The Oswald". I don't know what choice of toppings there are, if any. Price is $11.99 and is served in souvenir Mickey pants.