My advise is to go Werner, but that is because i want to see more people on there.
I'm a little biased!
Nieldo, it's quite difficult to say which is the best weapon really. I could spurt out several pages of statistics about damage degradation and Cone of Fire bloom but i doubt i would achieve much. I would say the Rifles (assuming you are talking about Medium Assault here) are all very balanced. In terms of Heavy Assault though, things get a little, tricky.
There is much debate over the balance of the Heavy Assault category. Here's my take on it:
HA is balanced IMO, it just requires different styles of players to make the weapons work.
Vanu Sovereignty (Lasher) - Best to work in smaller teams of 2/3 people. It has slow moving orbs that do medium/high damage. They also do a small amount of splash damage so you *can* technically get people around corners. But it isn't that useful.
New Conglomerate (JackHammer) - Short range, high powered shotgun. Can kill an enemy in near 3/4 shots provided you have a good close quarter combat aim.
Terran Republic (MCG) - Claimed to be the weakest HA, i disagree. It definately requires the most experience to use and a good overall aim and control of burst fire. It has a high rate of fire with pretty low damage. It has the slowest Time to Kill (TTK) yet i firmly believe that it's slight range advantage over the other 2 HA makes up for this.
Malc30, I'm glad you seem to be enjoying it! Unfortunately you are joining a very experienced playerbase that have formed their own little tight groups of friends. It makes this game very n00b unfriendly. What empire did you join? I might be able to suggest some helpful players and outfits to give you a hand.