1.) Since you did not state a budget, I recommend either the ASUS P5B-E
($151) or the ASUS P5B Deluxe
($180) depending on whether you want to SLI or not. As for whether you need SLI or not; One 8800GTX is more than enough for now, but you may want to consider the possibility of buying another one in the [far] future when the 8800GTX starts to lose its top-end position.
2.) eVGA and BFG are both excellent and reliable companies, although eVGA is usually considered to be the best GPU manufacturer bar none. eVGA also has their step-up program, that lets you upgrade your videocard to a more advanced version and only pay the price difference (provided you have the original invoice), but it is limited to 3 months time. Is there a difference between the two companies? Lets just say that you'll be happy with either of them.
3.) If you don't overclock then the stock coolers on the two pieces of hardware should suffice. Factory speeds are certainly impressive on the Core 2 Duos, but overclocking has its own reasons. With overclocking, you can take a 2.4Ghz E6600 to 3.2Ghz or beyond. This kind of potential is unrivaled, and has been unseen for years. For me, not overclocking is not an option. Since it is without significant risk, it's a no-brainer for me to increase the speed of my processor with negligible detrimental effects. I consider not overclocking to be akin to taking a 3.2Ghz+ processor, and underclocking it to 2.4Ghz, for no apparent reason. Even if the 2.4Ghz is enough for you, I do not understand why one would want to run their processor at a slower speed than it can handle. For this reason, I would also suggest you go with the E6600, since it will overclock just as far as the E6700.