Cheap device to use as wireless extender and wireless hard drive

I work offshore and one of my main sources of entertainment is to sit in my bunk and use a tablet to watch films etc. and other content I bring from home, usually recorded off my HTPC or ripped from DVD's. I do have a home media server onshore but the internet offshore is almost unusably slow and certainly won't support any kind of streaming or data transfer.

I have a Nexus 7 with 16Gb storage and find this pretty limitng and end up transferring files regularly from my various USB sticks and hard drives.

A lot of the guys have gone out and bought wireless hard drives like the Seagate ones (Seagate Wireless Plus), apparently they work very well. Is there a low cost equivalent using my existing storage?

They are expensive and lack flexibility. I am looking for similar solution with which I can use my usb drives, hard drives, memory sticks and ideally as a wireless extender onto the existing wifi network. I don't need a LAN port or any kind of modem. The idea is to give me access to all my files on my tablet as transparently as possible so I would prefer a solution which does not need proprietary software on my Nexus.

I guess the perfect device would be a budget wireless router or USB hub (second hand?) which has multiple USB ports supporting storage and can act as a Wireless extender. Perhaps there are devices on the market which fit this niche? Maybe a cheap router like this one?

Any suggestions?

Cheers

Chunks