I've been round this loop with an old Land Rover. The replacement shoes are much too hard, there is a widely used lining spec for aftermarket parts (an EU requirement and a lot of this stuff comes form Italy) and it specifies a wear life but not a friction rate so they are all much too hard.
For the Land Rover I phoned loads of suppliers and found Borg and Beck did a high friction set - they are amazing. Doing that I also found a number of specialist brake re-liners who specialized in classic car and bike racing and would re-line for as sensible price - about £60 a set and would guarantee braking up to modern standards. Pity I can't find the list now but if you search under classic racing brake re-lining you will find them.