That's what Id do but where I buy from don't really tell Mr much lol but they are a lot cheapeso I'd just have to look into that some more I guess
Same here, not having problems with the prop valve that my car came with, even beating it to the point of melted tires on Hockenheimring .I was about to go and cross-reference part numbers at Majestic Honda - The Internet's #1 Honda Automotive Parts Store to check compatibility, but you can do that too.
As far as the proportioning valve, every single 4040 valve I picked up had issues- I ended up using my stock prop valve and everything was ok- even after I upgraded to 11 inchers all around. It may not have been ideal, but I never had stability issues while braking through a turn. If you measure pad and disc temps though, it might be a different issue.