Weapons for war

So I was thinking about which would be better, a power weapon or a plasma pistol.
Ok The detales.
Im looking at a guard list Id like to run and I'm wondering if my men can win with out close combat. Sure CC will happen but what If Im not geared for hand to hand but a solid short ranged shooting? Exploit my balistic skill over my lower Initiave. Space marines and their satistical ilk abound! And they will kill my me no question. I think a plasma pistol would be better and get more use durring a game. with a speed bump in front of a command unit I could shoot inflictkills have my speed bump take the hit and my command couls either get away or live to shoot again.
I have been told that the best way to use guard is to lean on a target unit with a pltoon of guards men. not to get into a squad on squad senerio.
My current "load out" has a huge amount of plasma. 2 full pltoons with plasma guns The rumor is that squads will get one or two more "special" weapons avaliable per squad. I can't see 3 plasmas per squad but two would still be very good. I dont know where this outs command squads as far as MEQ killer guns are concerned.
These rumors make it hard to make any good informed descions about my armies new derrection.
But I'm thinking the more strong shooting I can get the better. Another worrie is scoring units or rather their survival. My pltoons will give up loads of kill points At ome where near 6 points per full pltoon.
This makes speed bumping a tuff choice. Not a bad choice but a hard one to make. oh well we'll cross that bridge when we get there. Guess I'm getting way ahead of myself.

This has come about because of a teal turney I may make it to in may. I dont know who I will team with for sure or how many points I can spend yet. Im expecting anywhere from 750 to 1500 at most. but who knows. I want to provide the most versitial army posible to alow for a big win. I will have not played for about 6 months by the time of this event.
I'll be lucky to get 2 trainup games in at most befor hand.
I'm refuseing to play marines. That's all I know for sure.