Cargo Bikes

I'd quite like to find some dust seals for the ball steering ball joints only one of four remains and it's fucked- they were pretty dry and rough. I've greased them but I'm guessing without seals the grease will quickly become a grinding paste.

I also ordered a right hand disc lever for the front brake as I can't handle the euro setup and a quick google suggests these master cylinders don't like being upside down, sounds legit.

Other bits needed include

1. A nice set of tires that come in both 27.5" and 20". I reckon I've got around 2.2 inches of clearance front and back. It's surprisingly hard to find a pair.
   
2. Mudguards! I wish SKS did pick n mix. How do folks do it on their cargo bikes?
   
3. I quite fancy one of those back wheel locks like in Holland. I also don't live in London so it seems a feasible way to leave it outside a shop for 2 mins.