From a fellow Firefighter i.e me
In my tunic I carry a generic non serrated locking knife for emergency cutting free duty ( guidelines, wires etc etc) this has a chunky handle as well as a great big karabiner and lanyard on it that I can open it when wearing my fire gloves, it has a curved point rather than a drop point. On my belt for general day to day I carry a leatherman, you will end up using this tool every shift I guarantee you.
Don’t worry about the ‘legality’ you have a justifiable reason for carrying a locking blade in a public place. That and the last thing you want when all caught up in wires or line is a blade that can close up when you’re using it one handed.
In my opinion a knife with pen clip will get lost easily, better to find one that is capable of being ‘attached’ to you.
Also get your service number and station engraved on it, that way if you drop it or loan it out at a job it should return to you.
P.s the shiney rescue knifes generally are bobbins and appeal only to people who don’t actually need to use them.
P.p.s get a toffee hammer and seatbelt cutter in your tunic for r.t.c’s