Peter
IMHO the blade type of stabilisers work as well as the Alko type. The advantage of Alko stabilisers are convenience, once fitted you only need to couple up and clamp down. Also they eliminate coupling rattle, and you can fit an additional security device that prevents the van from being uncoupled. However they lose their effectiveness if the ball or pads become contaminated, or the pads become worn.
At the end of the day it's personal choice. You can often pick up second hand blade types at caravan dealers or on places like Ebay for a fraction of the cost of an Alko, so it wouldnt be expensive to try one of these first to see how you get on.
As far as wheel clamps are concerened, go for one that covers the wheel nuts. The Sold Secure ones are expensive but some insurance companies offer a discount if you use one.