There is no better brand better for LFS, simply the most powerful - AMD's 64 -bit lines kicked the hell out of the slow, hot Pentium 4's, but Intel came back with the Core 2 Duo's which had a better architecture - on paper, an AMD is 2/3 faster than a P4 at a given clockspeed, this is why they sell CPU's such as the AMD 3700, designed to be the same speed as a P4 3.7 GHz, which only runs at 2.2 GHz - however due to the better architecture of the AMD it's actually a little quicker. It's also quieter, too.
Intel have done the same, and made it so that for a given clock speed the Core 2 Duo is 3/4 more powerful than the AMD 64 CPU, and twice as fast as the P4 - meaning that a lowly entry level 1.86 GHz Core 2 Duo is technically just as quick as a 3.72 GHz P4, however in reality it is alot quicker.
You can't really use clock speeds to compare them, but the basic rule is that Intel Core 2 Duo's (C2D's) are the best, and if you can't afford them (which is hard when you can pick up a CPU, a GB of RAM and a mobo for inside of £130), then AMD have some great budget chips like the 3600 x2 Brisbane which can be overclocked.