PouchDB dev here. Obviously I'm biased, but here's my take:
The best way to get around the storage quotas in PhoneGap/Cordova is to use the SQLite plugin for iOS/Android. The performance also tends to be better, especially on Android. (Edit: in modern post-Kitkat Android, it's actually worse.)
WebSQL has a nice query language, but you want to be future-proof, i.e., not chain yourself to a dead standard. There's also Windows Phone and Firefox OS to consider.
So if you use PouchDB and install the PhoneGap plugin, it'll work cross-browser and you'll avoid the storage limit on iOS/Android. Win?
Also, it's my personal experience that Angular fits with PouchDB like PB&J, since Angular deals with straight-up JSON objects and so does Pouch. (Compare this to Ember and Backbone, which have custom classes that you have to export to/import from JSON – it's a little trickier.)
Good luck with whatever you choose!
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