There is the free WWG Health Tracking app, if you have a phone around (e.g., from the Google.Play store: https://play.google.com/store/apps/details?id=com.whitewizardgames.lifetracker ) or there are a whole bunch of free, non-branded apps that do the same thing you can check out.
Otherwise, poker chips would also work; they might not be numbered, but you're only keeping track of two- or three- denominations, so it's not too hard (or, you just count with 1s and 5s, further reducing the memory work).
Amazon UK have the 240 card box here, from 3rd parties only: https://www.amazon.co.uk/dp/B01N213MUK/ref=cm_sw_r_cp_apa_i_dH51Db3PCW4D8
However a new, much larger box was in the recent Kickstarter and coming soon: https://www.shop.whitewizardgames.com/collections/frontpage/products/hero-realms-adventure-storage-box