Bicycle Mechanics - Newbie q: stem compatibility

I've never dealt with changing stems before, so I'm not familiar with the issues. I have short arms and have had hand pain in the past, so I want to keep my options open for my new bike.

I'm looking at the Novara Forza, among othes. It has flat handlebars with an ATS adjustable stem. This gives it some vertical adjustment, but no real fore-aft adjustment. Would an off-the-shelf angle-adjustable stem be compatible with this? Or is that even the right approach to take?

I found a nice blog post (http://biketestblog.blogspot.com/2005/06/nvo-components-ats-stem-revolution.html) on the NVO ATS, which describes both the shim and a proprietary headset cap. I assume the Novara ATS has a similar design. Is there any way to tell if the outer diameter of the shim would fit an off-the-shelf stem? Or even if it would be safe? If not, could I assume that I could remove the shim, use a standard angle-adjustable stem with standard spacers, and that the headset cap wouldn't be an issue?

(For what it's worth, the other bikes I'm considering are the Cannondale Adventure 3/4 and Trek 7300/7200. I realize these are a step above; the only reason the Forza is still in the running is because of the sale price; Novara doesn't seem to have anything in the same class as these two.)

I found a nice blog post (http://biketestblog.blogspot.com/2005/06/nvo-components-ats-stem-revolution.html) on the NVO ATS, which describes both the shim and a proprietary headset cap. I assume the Novara ATS has a similar design. Is there any way to tell if the outer diameter of the shim would fit an off-the-shelf stem? Or even if it would be safe? If not, could I assume that I could remove the shim, use a standard angle-adjustable stem with standard spacers, and that the headset cap wouldn't be an issue?

For that system, you use a shim over top of a standard steerer tube. For that reason, a standard stem will NOT work with the ATS system. ATS stems must use some diameter larger than 1 1/8" (current steerer tube standard) to be able to clamp onto a shim that goes over a 1 1/8" steerer tube (due to the thickness of the shim).

I see no reason why you could not remove the shim and use a standard stem on the Novara though. The fork is not proprietary so it must have a standard 1 1/8" steerer which will be comaptible with any stem of the same size. You'll probably need a new top cap though which will not be included with most stems.

The NVO shim is keyed, you eitehr use the NVO shim with it's proprietary stem, or you don't. Once you take the shim off, your fork is any regular threadless fork.

Thanks for the responses. I was able to look at the bike in person, and it is indeed an NVO stem with Novara branding on it.

As things worked out today, I've decided to go with the Canondale. That's partly because I wasn't able to test the Forza on a hill (not available in my size), but largely because today I was served by the LBS owner instead of his staff, and was impressed by his knowledge and approach to fitting and training customers. REI has good overall service, but just can't provide that level of personal attention. It's worth the extra couple hundred.

Nevertheless, I'm appreciative for the time taken to answer my question here.