Sorry to hear that your fundoplication did not work. I believe at the moment Endostim are not accepting candidates who have had a previous Nissen, but it might be worth sending them an email to see if their criteria has changed.
Endsotim is not available on private Insurance and I believe the price in the UK is now £17,000 - 23,000
There was a recent article in the Daily Mail about it, if you search on Google, and there is a page on Facebook for the Endostim where you can ask questions of those who have actually had it.
If you search this site for Grover Cat, she has recently had the Endostim done in Germany as she lives in the USA.
Hope this is of some help,