I know nothing of Roman currency of the time.
I would like a cheaper option (although/because I realize nothing will be 'cheap') which is not too worn.
I know they are for sale on eBay, but I don't know the difference between the various options.
I would suggest you try /r/Coins and /r/AncientCoins or /r/Numismatics. They probably have more expertise in collecting and purchasing old coins.
This won't answer your question, but I feel obligated to inform you that purshasing cultural heritage is illegal after the 1970 Unesco Convention. You're thus better off ethically, legally and monetary to buy a modern look-alike.