Harlequin-floors are indeed the best dancefloors I know about.
They are used worldwide by a lot of famous companies.
If you are looking for a less expensive non-slip finish for your woodenfloor there is no simple answer.
Unfortunately in my country specifications or standards for dancefloors don't exist, so one have to 'work with the more common sportaccomodation-rules.
I suppose you have an existing wooden floor that has been waxed or varnished before ?
A wooden floor that has been waxed is extremely difficult to put another type of finish on, because the wax will have saturated the wood. (sand the floor extremely well and wash away with a strong solvent) Better leave this work to a professional !
A lacquered or varnished floor can been stripped with a degrease-product, change product as often as possible.
I would suggest to ask a professional in your region for advice.
Years ago I had a good result myself with a simple dim (hope this is the right word ?), waterbased varnish.(polyurethan-acryllic) (note : this result is also depending on the condition of your floor)
Waterbased because it is much easier to apply the product and the drying-time is shorter....
This type of finish is easy to keep in a good state of repair and you are quite 'safe' for about 10 years.
Do realise that a good floor-finish depends also on the fact if one has respected the neccessary drying-time !
Most products have their full strenght after about 1 to 2 weeks....so, you can walk on the floor but not dance !
There exist products on the market that are used by professional companies : you can find lots of interesting info on this website : http://www.stagestep.com/
click on 'guide for floorcare and maintenance'
They recommend some non-slip finishes for wooden floors aswell.(Profinish & Proseal)
Unfortunately they are based in the US but there must be simular products available in UK.
Please read also their issue in 'Flooring & floorcare tips gone by' : "The environment and your floor", on cleaning and (really important !) the humidity in the studio !
Hopes this can point you out in the good direction