Hi Crazy Neo,
From experience, I can confirm that this one is a very reliable Rockchip player:
MP4Nation are a reliable source, and of course there are others out there. I have also bought a couple of Rockchip players from Ebay, reliably too. They tend to have a max capacity of 2GB, (although 4GB Rockchips are around now).
If you do a quick youtube search for ROCKCHIP MP4 I think you'll see some good Rockchip demos. You'll soon see that they all generally have the '7 tabs across the bottom of the screen' menus.
For around €100, you can get some very advanced players e.g. Ainol, Hacha - even Meizu etc. Again, have a look at MP4Nations site, see one you like and then do a search for it at Youtube.
Before you buy one, it might be worth coming back to this forum and asking people (as you have done already) whether it's any good if you're not sure.