[volt-nuts] Best Vref part ?

[Fred Schneider]

I want to make some good ( better then the ones I made) Vrefs. Better as in longtime stability and tempco. Just for fun.
The ones I made upto now have a short time drift of 1 to 3 ppm, longtime ?? They are on for a month now, and begin to stabilize.
I have the schematic from Warren that uses the 1n825, i can buy that from Farnell.
I have a schematic that uses a LT1021B, also for sale at Farnell.
But I have read about LM199/299/399 that is temperature controlled
LTZ1000 that should be very good and VRE4100 but non of those sold by Farnell.
What is the best option ? I am not a company so I can not order evereywhere. I can buy from R&S, Farnell and Conrad. I have no ebay acount because I do not like auctions and bidding.

Fred PA4TIM