Ah you say that, but compared to most bookshelf's those mordaunts are pretty small, they're not mini, but they're smaller than most. I personally think due to the shape and way they're designed to look, they definately feel smaller than my mission 751s (I bought some 10yr old missions from the auction site, about 8 months back, whilst my mate went for some mordaunts brand new, as we both decided to make the move to better quality audio at roughly the same time, so I've tested and heard both pairs

).
902i measurements:
H: 290mm
W: 165mm
D: 265mm
Also looking at richer sounds, perhaps the JBL Control 1 speakers might suit your purpose better? Roughly 20cm tall, so much more similarly sized compared to standard speakers, and pretty cheap, so even if sound quality isnt quite as good as more expensive hi-fi gear, it'll probably be better than most pc systems and they only cost 50 quid, they're in silver too, and a lot of people seem to have silver monitors/monitor stands/keyboards etc
H: 227mm
W: 130mm
D: 140mm
PS. The 540R AV Amp also comes in Silver as well as black, so again you could match the two, and then upgrade the speakers later on when you come to improve the setup to surround sound
So you could buy both brand spanking new for around £300, which might appeal to your budget, and warranty desires, or buy the amp or speakers second hand to make compromises for budget.
-edit Found this quote in a mini review on those JBL mini monitors I just mentioned 'They can cope with surpisingly high wattages to give some real punch for their size and their frequency response is excellent.
Basses are surprisingly good considering the small size of this speaker. Mids are decent and have a very high definition and quality. Highs are accurate and real. This speaker doesn't sound tin like.
The only real niggle is the slightly flimsy wall mount which could have been thought through better. At least it's not going to fall off your wall though!'