I haven't heard of a comprehensive list or website that shows you all the coins made for a specific date, but you can probably use a generic coin database program or website to find them all pretty quickly;
try the NGC website, for example, and enter "Great Britain 1985" in the first search line. It gives a picklist with the dozen or so denominations that were struck that year. Click on each denomination in turn to see if multiple types were issued of that denomination (for example, the 1 penny comes in two flavours, Maundy and regular).
It's also up to you if you wish to consider proofs as separate coin types, and therefore required for your collection in addition to the circulation coins.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis