I would stick with 10 speed - I'm swearing by the Xenon 10 speed QS shifters. You can get a new set with cables for $79. I know because I have a set of these installed on my wife's bike with a 10 speed drive train (Actually have an 11 speed rear Athena but other than that they shift great) The levers are black alloy but the inner paddle is plastic. Some people like to trash the Xenon set but It's all BS it shifts great. However if your looking for a Silver colored lever you may want to consider other options.

You won't really need a long cage rear derailleur even with the 12-32 cassette. You will need a medium cage though. Obviously you won't get smooth operation when you shift into the Large large combo but your not supposed to do that anyway.