Moving Hot water header tank up the loft

Hello, we have recently moved into a new house and in the airing cupboard is the Hot water cylinder, a header tank which I think is only for the hot water cylinder and an FandE tank for the central heating
I would like to move the header tank and FandE tank into the loft, The F and E tank I’m confident will be fine, and will just involve moving the cold feed, the outlet the overflow and the expansion to go back over the top.
Is this the same for the hot water Hot water header tank, cold feed, outlet, overflow and expansion? there is a pipe like the expansion on the FandE tank, that is bent over to return into the water tank.
It is an old copper tank, so was going to replace it with a plastic one, will this need to be a "bye law 30" tank? or is that just for drinking water?
The loft is well insulated and will ensure that it has a very sturdy platform,
Is there any thing else that i will need to take into account?
I have a standard boiler ideal icos, and hot water cylinder which is staying in the airing cupboard. There is secondary heating into the cylinder from a log burner and connected to a single radiator too.
Many Thanks
KW