First up - Appropriate Mocking: Read the forum rules and post in the correct forum - questions and spoilers go in the (surprise surprise) Question and Spoiler Section!
Here's A Link
Second - "Best" weapons are hit and miss, depending on your roles you're going to stick to (There's only a small number that are actually useful though). There's a HEAP of info in the Spoilers section on weapons and their upgrades etc..
Check out the weapons upgrade forum in the Spoiler/Questions Thread and read through that, if there's any questions after that, post them there and avoid the flame throwers.