jonb: The tp-link one has a very good reputation here on geekzone, if you look through some old threads..
I bought myself a vodafone complete hg556a from trademe, I've has no problems with it personally ( I don't use the file storage or 3g backup capability), but I would probably get the tp-link one if I was buying again.
+1. I got one for my PIL about 6 months ago after reading through geekzone, I don't know if it meets all your requirements (mainly because I don't know understand what some of them are, haha) but I found it easy to set up and it has been super reliable for them, they use it wired to 2 PCs plus use it wirelessly for an android phone and an iPad. Pretty good value for the price.