Planning to cook in the cockpit with the stove between your knees? I'd check my insurance first. It just might not fall over in the marina, but elsewhere??
Isn't the tall one what they use on ocean racers to cook their seven different(?) flavours of porridge?
IIRC, both types (if fixed properly) meet BSS regs if they're stored outside when not in use, so presumably fairly safe. You couldn't do a brew at sea with the flat one, though - too much danger of flying kettles!
You will find this kind of stove on any Open 50/60 and on some of the MiniTransats etc. A lot of very good sailors use them. Nomally "gimballed" with shockcord! Though my First Class 8 had a proper frame to take a medium Camping Gaz bottle with a burner screwed on.
I've got one of the flat sort for camping/road trips and it is very good, cheap £10 from Trago Mills. Boils a kettle in about 5 mins. A chum has one on his triamaran. The gas cylinders are easily found and last a surprisingly long time.