I did the full Eton speaker upgrade. At the time that the JBL advice came out, Eton did not offer a replacement set that would fit the rear properly.
I even went ahead and added the Eton CENTER speaker, against the recommendation of others.
Its worth the money. If you have the base/hifi sound system (anything other than HK) you will need to source door sails to mount the tweeters into.
A few options exist.
check out my thread, I detailed it pretty specifically including parts.
https://www.2addicts.com/forums/show...php?p=24919868