Uncertain on protein

I'm a little at sea on my protein goals right now, due to conflicting information.

I definitely don't want too little, because to the extent I want to lose weight, I want to lose fat, not the muscle mass I've already got; in fact, if anything, I'd like to add some more lean muscle. But how much is needed? I've seen different levels -- for instance, there's a fairly complex calculation in Protein Power that gives me about 65-75g, a simpler calculation based on 1g/kg weight that gives me 72g (but I've also seen other factors than the 1g, anywhere from 0.6 to 1.2, which would give me anything from 43g to 86g), and a simplified chart in the Protein Power Life Plan that gives me closer to 100g.

On the other hand, I think there's a "too much" out there, even though it's even harder to define. I've seen some numbers like 2g/kg/day (which would be about 154g), but the implication is that that's a steady level, not a single peak, and the problems that's supposed to cause aren't well specified. And then I've seen a lot of vague warnings about kidney problems, but usually more of a "may aggravate" thing, and my kidney function is fine (according to my recent lab tests). And then there are less serious but not pleasant problems, like carnivore breath, which is the result of ammonia compounds from the breakdown of excess protein being disposed of by exhalation.

Right now, I'm going with a goal of trying to keep my protein intake between 75g and 100g daily, but I'd definitely welcome some input that would let me either refine that or be more confident in either my upper or lower bound.

Late-breaking addition!: Conveniently, today Jenny, who blogs at Diabetes Update and runs the insanely informative Blood Sugar 101 site, put up a protein-needs calculator. Depending on activity levels, this gives me anywhere from 63g to 91g of protein needs. Given that my actual levels probably fall somewhere between the two, I think my current goal of 75-100g is probably still in the right vicinity.