Im after a 210 litre indirect unvented cylinder that fits - or nearly fits a kitchen tower cupboard. Most cylinders seem to be 550mm diameter and system-fit versions of models like megaflo and santon show that the overall arrangement including pipework/pump etc measures about 700mm deep. Options for reducing this appear to include Ariston Primo at 505mm dia but theyve got a bad write-up on here. Range tribune slimline at 478mm dia is 2m tall so there wouldnt be space above for the expansion vessel. So it looks like Im stuck with a 550mm dia tank....Can anybody recommend which cylinder ends up the smallest (both width and depth) once all the kit has been fitted?