Iam using the "Shims under the Bucket" conversion from Arnout (NL) which should allow rpms to about 10.000 with some other mods. They are much lighter then the original one and work fine, now over 20.000 km.
when i had the cams off trying to re-shim the buckets i thought about going to the shimless bucket route but lack of time i just used the stock shims. if i ever take them out again i'll put the fancy buckets back in.
Did you go down to Lab Kerri? I brought Rich there the first set for my 7M. They work pretty well. Not needed unless you are going beyond the norm with big cams though. IIRC, the Echo has the proper size for the 2JZ. Price wasn't too bad from Jeff Watson.