Hey St Peter,
I have used Rocna with 100% success. Sets every time, automatic reset with tide/wind change and never drags. Everyone I know who has one says the same.
They have a nice video
http://rocna.cmpgroup.net/film which also shows their newer design (Vulcan) which doesn't have a roll bar so may be an easier fit in your anchor locker. Sizing guide
http://rocna.cmpgroup.net/anchor-sizing-guideInterestingly the Vulcan looks very much like the Spade which also has an incredible reputation. Pretty sure I saw one in Four Winds Marine Geelong.
In 2004 when I was looking for an anchor for my Top Hat, I searched the web for ages and finally imported 4 kg Oceane from Jersey. It would be similar fluke area to the 6kg Vulcan and fitted nicely in the anchor locker. The Oceane was a cheaper offering from Spade and was replaced with the slightly redesigned Sword. Not sure if Sword is still available.
I have not used my Oceane in stronger wind than 30 knots but it was just as reliable as the Rocna during 11 years of use.
One time I had a Mottle 33 tied up to the stern of my Top Hat off Port Melbourne in gusty wind and the Oceane just buried itself deeper and took some patience to get out later.
I did not sell it with my Top Hat but had it re-galvanized and now use it as a lunch pick for my S&S34.
In regard to tackle, I had 25 feet of 8mm short link chain with a proof tested shackle and 50 meters of 16mm nylon 3 strand rope. I always use a piece of plastic tube slipped over the rope and taped on to protect it from chafe from the cheeks of the bow roller.
See you around Queenscliff sometime,
Tom.