I started building that dam with Engineer's Toolbox. I have to say that's a really nice and realistic solution, if you can find a suitable river (which should be no problem at all in most worlds). You can stack the Hydroelectric turbines 24 deep (they work between elevation 40 and 64 and make the dam as wide as the river. That's 240 RF/t for one horizontal space. I don't think you'll get that with any other type of power generation this side of nuclear power. I found a river whose "river biome" part is about a chunk wide, makes 3.84 KRF/t on 16 horizontal spaces should I fill that all in.
Outfitting the sockets is a bit of a hassle, since you can't rotate them so you need to put modules in the bottom before you place them. Totally worth it though. Low to medium-level power with no logistics involved at all. Just build the thing and connect your cables. The modules even accept Buildcraft facades so you can make them look like anything.
Also, crafting is easy and doesn't require any machines, and the resources needed aren't all that rare. Apart from some regular metals and redstone, just a few gold nuggets. The blank modules need a little glowstone dust (1 per six) but that shouldn't be a problem if you play Monster - Infernal Hives aren't that rare.
Edit:
For working underwater if you don't have a powersuit yet: Mariculture's diving suit is very easy to make.