We insisted on getting a high-level cistern to replace our old one when it finally cracked. They're not easy to source! We had to visit a manufacturer in the end, which fortunately for us is based only twenty minutes away.
Sadly, modern cisterns are not allowed to hold more than about two-thirds of the water of the old ones. This is an EU measure to conserve water. As a result, it now takes several flushes to get rid of traces whereas the old cisterns used to manage it with one flush.
Penny wise, pound foolish.