[QuarianRex]

I didn't see anyone mention this, but you can enable the "view complete tech tree" option in setup (the game mechanics section I think).

While in the game there is a button to see the tech tree in the bottom right of the research queue. This lets you see it from two perspectives, both to see which tech areas unlock other tech areas and to see what is available at each tech level.

While it doesn't provide any stats it does give you a good idea of what you can get.

As far as what the 'best' weapon is, it really depends on what you like. I am currently quite fond of the humble meson bLaster. It has a good range (6 I think), good damage (35 at maw IIRC) that doesn't drop with range, and is as light as a feather (well, a 20kt feather anyway). I enjoy having fast meson equipped ships set to max weapons range (prefeably with some sensors or a religious talisman). It seems to work quite well.

Of course, this can always change. I next plan to break in null-space weapons and see how I like them.

Also, don't get too caught up in relying on damage factors and such as an accurate measure of a weapons worth. Each weapon has its own personality that takes some getting used to, and simple changes in support components, ship strategies (important), and even the order that the weapons are placed in can turn that useless P.O.S. that you just wasted two years researching into the Fist of God that you hoped it would be.