Well, everything I have read about the F80 positively raves about it from 'Stuff' magazine to Stereophile.
I saw one in a branch of John Lewis two days ago and it looks amazing. (Regrettably there was not time or facilities to listen to it.)
If you buy it and end up eventually hankering after a full size system then I am sure you must have other rooms it can perform in once you have recovered financially.
A normal full-sized system will not amaze your friends though 🙂 I have read one person explaining that everyone in the room assumed his Quad electrostatics were producing the sound!
Amazing your friends (and yourself I hope) is probably a pretty shallow reason for such an expensive purchase but hey, why not have some fun? There is little enough of it around nowadays!
In your situation I would get the F80. It is unique, sounds great, and will probably become a classic very quickly. Everyone and his brother have got something 'vanilla' like the Marantz combi. As nice as the Marantz stuff undoubtedly is, I think you are going to kick yourself if you don't get the F80.
Enjoy whatever you decide on.
(If nothing else it is good to hear of something that makes a Bose look and sound like a Binatone! At least with the F80 you are getting the goods for your money and not woofle dust.)