Tony, Anchors seems to be discussed at great length over on
www.YBW.com.
Probably the best of the bunch are the new Rocna / Spade or Mansom Extreme anchors rather than the Bruce or CQR, however they come at a price. How they can justify £400 for 10kg of steel dipped in galv is beyond me.
On the yacht we use the Delta which does well in tests and as a spare the Fortress Aliminium also highly rated. Probably a case of borrowing an FX7 and see if it will fit. If not then the Spade which is available from Jersey would be worth looking at. It also comes apart which means it may well fit a small anchor locker.
http://www.spade-anchor.co.uk/
There are a number of copies for Bruce, Delta et al. However the quality is dreadful and whils tthey bear a resemblance there are small differences in shape which may afect the tip weight which is required to get the anchor to dig in.
The Rocna website does have a lot of useful information on anchoring, however just be aware they have been caught modifiying test data to suit there products rather than show the true results from Sailing magazine test
http://www.rocna.com/
Pete