All funds are pretty much the same as far as the sleeve goes. There is a one year waiting period before you can have it done.
In my opinion, it is worth the wait, as out of pocket can be more than $20'000.00.
If you are in a fund, out of pocket expenses are no more than $6000 depending on your fund.
If you can afford $20'000 then go ahead, but you can use the year to work towards the operation, by losing some weight, and researching Surgeons etc. Join a fund tomorrow!