Any question answered...

Brilliant, thanks a lot!.

So having only one cog, can it still be a freewheel, or does it accept only fixed track ones?It's a shame that that you need to choose only one:(

Unfortunately in evans don't have the Fuji feather on my size, and I'm tied to the ride to work schema with them.
What about the Fuji 2.1 track? it is a bit flashy for my taste, and some reviews out there complain about some details, but I could live with that... Is that one any good? And does it come with a flip flop hub?

Cheers!

You should use a track cog on a track hub. Have a read of the answers on this page here, they explain how the two different systems work: http://bicycles.stackexchange.com/questions/11269/how-do-i-change-my-single-speed-to-a-fixed-gear

The Fuji 2.1 track will have the same problem, in that it's fixed-only (don't look for a single speed bike in the "track" section!). What about a Genesis Flyer? That has a flip-flop fixed/free hub: http://www.evanscycles.com/products/genesis/flyer-2014-singlespeed-road-bike-ec055507