I've read a number of articles that say placing the frame on a number
of strategically placed patio slabs will suffice; others that say I
need to bore a number of holes and make some concrete pillars !!
Obviously the first options sounds far more appealing, but will it work
properly??

Personally, I would do it the way I did for my conservatory base. I dug
cubes of earth 450x450x450 with a spade and laid breeze blocks on their
sides. 8 per hole, jointed with mortar, with a small amount of wet concrete
poured underneath and down the sides to backfill.

For decking, I would probably use smaller holes, i.e. only 4 breeze blocks
in two layers, digging about 220mm deep.

Christian.