Ventilation required for sitting room fire

[sarahw]

I'm considering putting a wall mounted, flueless gas fire into a flat I'm renovating to sell:
http://birmingham.gumtree.com/birmingham/37/47397937.html

I've got a mate who's a gas fitter who can connect it for free, but says it needs venitaltion of 100cm2 and I can't access the external wall (tiled eave) and think a window ven would look outdatedand hideous. He also thinks I wont be able to useteh chimney stack I'd like to mount it on because even though the chimney'snot capped he says it's not a fresh ar supply.

A few questions:
1. What are people's views on these fires? the flat'sin SOuth London and will be for commuters.
2. Anyone got any ingenius ideas for venting it?

Thanks,
S