PDF annotations and sync

[pepeday]

Hey there, coming from an inkBOOK ONYX (for which you can see a review here), for which I have developed a love/hate relationship.

All my ereader needs are actually covered by MoonReader+, which is to say that what I'm looking for is:

1. 6+inch reader with frontlight
2. epub (mobi) and PDF support
3. Annotations both on epub and PDF
4. PDF annotations: highlight, bookmarks, comments and adding text
5. And finally, being able to sync all of these with the cloud (ideally, Dropbox)

The inkBOOK is actually not half bad in either of the above but the unit received had a crooked screen and there are some dreadful software design flaws I cannot stand.

I have been reading for koReader on the Kindle PW3 and Kobo Aura HD (or even Glo HD), so my question is, what's your suggestion for finding something that would fill my needs above?

Thanks