The
clamp you linked is made for aquacomputer
aqualis reservoirs which have an outer diameter of 75 mm.
Neither the 60mm or 80 mm tubes you linked will fit exactly... can you make it work? Perhaps.
The
cap you linked is also made for an aquacomputer
aqualis reservoirs and is a different diameter (75 vs 60/80). The cap also does not secure to the top of the tube by threading onto the tube, instead aqualis uses an inner stainless steel tube to secure the top to bottom, with a pressure fit to the reservoir tube.
If you wish a multiport top, it may be easiest to use the
aquacomputer D5 pump top which direct connects to a
aqualis reservoirs, which will fit the tube clamp and the multiport tube cap you specified, as one single. integrated unit.
Edit: If you decide to go with the aqualis reservoir, there are variations in size/capacity as well as upgrades. Just search for
aqualis base in their shop and you should get a comprehensive list.