I actually like the Stihl bars better, although for the amount I've used it so far, the Oregon Power Match has done better than my previous as far as wear characteristics. It was also the only 42" I could find for not stupid money. I'm pretty impressed however with its performance. My original 36" Oregon was well used and came with the saw.
The upside of the 088 is going to be power, the downside is that your bars are going to be harder to find and more expensive. The 066 uses the same mount as all but the tiniest Stihl saws. Not that you will need one very often.
Those are great prices on saws, BTW, my local Stihl dealer is a small local farm supply chain that doesn't deal, and the other guy close to my office is apparently on the "outs" with Stihl, but wouldn't give a deal to his mother. I've had a chain brake on order from him for about 6 months now. Farm store had it in 3 days. There are others around town that I will have to see when it comes to buying a saw. However, the new parts kid at the farm store is pretty good, he'll even order parts in if I call without making me come in for prepayment. However, after I bought my saw, I've got a new Husky dealer even closer to me who probably would deal on a bigger saw they wouldn't have to stock. Part of my reason to buy the Stihl was local parts availability at the time.
Have fun and good luck,
Mark