1" threadless is getting harder and harder to find. You pretty much have three options:
1) Old 1" mountain bike stem - however the handlebar clamps on these are 25.4 so not that usefull unless you run nittos bars.
2) Find a decent 1" road stem and flip it to get some rise, some are designed to do this.
3) Get a 1 1/8" threadless stem and use a 1 1/8->1" shim to use it on your fork. Some stems still come with 1" shims or your LBS should be able to supply you with one.
One of those will work for you, but I think 3 is probably the easiest option.
[Edit: curse you
LóFarkas!! - beat me to it]