Hi wild hair,
its very difficult to gauge what type of shoes you need over the internet! but the fact that your right foot is very flexible would indicate that you would overpronate during a walking motion.
however, from what you say, it sounds like you land on your midfoot or your forefoot, which then 'jiggles' around! there is nothing really on the market to control forefoot movement apart from a couple of top of the range neutral shoes -asics nimbus and mizuno creation?
This is just guesswork though, you really need to go and see someone who knows about running shoes, who can watch you run - from my perspective (working in a running shop) you can go into a running shop and ask them to look at your running style, for free (if they look blankly at you then walk out again!). Alternatively you can pay for your running style to be analysed by a running specialist physio or podiatrist, or there might be someone at the local running club who knows what to look for.
(oh and the asics 2090 is for mild to moderate overpronators - the support extends through the arch, for moderate overpronators, but the shoe is flexible enough that a mild overpronator, who only overpronates at the heel, can also get away with using it, though a 1090 would be the better shoe for a mild overpronator).