what size wire is used to supply the power? if you know this, then these are good guidelines:
20 AWG 5A
18 AWG 10A
16 AWG 15A
14 AWG 20A
alternatively you could put an ammeter inline and measure the current draw to determine the appropriate fuse
As far as glass or blade - use whatever is already present on other circuits so you can make emergency substitutions'and don;t need to keep two different types on hand.
