There are a LOT of different build-up and overlay type of 'hardfacing' weld fillers.
With different various properties.
Some for resisting impact, others for abrasive wear, etc.
With multiple vendors/maker/suppliers, there are literally HUNDREDS of different hardfacing fillers available.
From Stoody, McKay, ESAB, Bohler/UTP, Hobart, Lincoln, etc.
Some hardfacing fillers are available in SMAW (aka 'stick') electrodes, others are available in wire-feed form (usually in the FCAW variety, both FCAW-G dual-shield and FCAW-S self-shielded), and others are for use with oxy-fuel (oxy-acetylene usually).
What specific welding equipment/machine(s) do you have available? What is the size and thickness of the material you want to build-up?
Note that most actual hardfacing fillers are rather expensive compared to 'plain' steel weld fillers (stick or wire).
If you (or the boss) just want to build-up the worn face/edge of the roller brackets, you could just use plain steel filler electrodes. Which won't resist abrasive wear as well as an actual hardfacing filler, but might be 'enough' for the purpose.
Or go all-in some abrasive-resistant hardfacing. But you will have to choose even there, as different versions resist different abrasive environments differently.
Lincoln alone lists 15 different hardfacing rod/stick/SMAW iterms, and 15 different wire hardfacing fillers. Plus submerged-arc varieties.
Other 'brands' have similar choices.
You'll need to either look up things yourself, call or contact some different suppliers, or give us some more specific info to help YOU narrow down some choices.
And some of that info is just how many 'things' do you need/want to repair or build-up? As some of the fillers might be 'standard' catalog items but are really only available in pallet-level quantities.