Intel Core i7 920 (3.5GH with Turbo Mode) will this work?

Eeeek, AFAIK, you should never enable Turbo Mode if you want to do any overclocking.

Take a look at this: Intel Core i7 Overclocking How-to

the problem is many programs I use still utilize only one to two cores.

but with Turbo Mode disabled, how far can I get a stable OC with my specs?

A blanket statement that turbo increases instability is wrong (how many stating this actually have i7's and can state from experience). Mine was much easier to get stable with the 21x multi both with and without HT. One thing that seems to have some validity is they like the odd multis more than the even, but it seems each setup likes it's own combination.

Here are a couple shots of dome stability testing I have done both with and without HT enabled and all with turbo enabled.

I found your link to be very informative and interesting.
However, I do not think your conclusion is correct. In the article it states that they got better benchmarks with a moderate overclock and turbo mode than with a higher overclock without turbo mode.

Thinking about this, the use of turbo mode should be determined by the number of cores that your application can profitably use. If it is for gaming, where only one or two cores are generally in play, then the higher temporary multiplier would be best. If, your application can utilize all 8 threads, then the higher overclock approach would be better.