I have not compared your two faves but when I was looking for a tube integrated for a headphone system, I compared the Manley Stingray and a few other similarly-priced integrated tube amps (a Cayin amp - model forgotten, a VTL IT-85, Marantz 66, EAR 859 (and others in the family), and a few others).
Out of all of them, my favorite was the VTL (disclaimer, my main amps at the time were VTL 450s and with the right speakers, I love them dearly but am currently playing with super-sensitive speakers so am also playing with lower power amps) but the price was not right (but it would be if you are in the U.S.). I thought it had the best overall balance of delicacy and power, liquidity and punch. I ended up choosing the EAR 859 over the Manley Stingray but it could have gone either way.
FOR LOOKS, the Stingray is a winner. I also like the VTL but it's a bit more 'industrial chic.' I think several of the EAR amps have great looks. I don't know how they sound (only heard the 300B preamp), but the CR Developments amps have decently retro looks. The VTL, Stingray, CRs, and a few of the EARs (but perhaps not the 859) would physically fit your required space. If you win the lottery (or happen on a suitcase of unmarked C-notes), you could also look at the Electronluv amplifiers; almost any one of them would win my vote for "amp-most-likely-to be-featured-in-the movie-'Brazil'". Otherwise, for real retro, there are also the old W.E. amps which are each the size of a tall skinny fridge...
