I am an absolute Viper fan. At one time I had seven Vipers scattered across different systems for combat. If you focus on PVE in my opinion you don't need all A-rated stuff, just avoid B because it is to heavy. A ist best and most expensive. B is heavy but good, just not as good as A. C ist the best value for money: same weight as A and very cheap. D is lightest and better as E.
A few things to keep in mind:
1. Always upgrade Power Distributor to A and to the highest size possible. It will affect your performance the most. It determines how long you can shoot and how often you can boost and how fast your capacitors recharge.
2. Try to keep your total mass below or at the optimal mass value for your thrusters.
3. If you combine energy weapons and kinetic weapons alway make sure that at least one weapon category is gimballed (I would suggest the kinetics). Otherwise you can't bring all weapons to bear on a target at once, due to the different velocity of the beam and projectiles.
This is a combat layout I would recommend for USS hunting, RES hunting, Nav Beacon hunting and pirate kill missions. It is very cheap, teaches you to fight and with practice, you can bring down Anacondas with it, however it takes a little longer because of the missing shield cells meaning that against an Anaconda you might have to let your shields recharge. This build is so cheap and the rebuy is laughable that you really can try everything an push yourself, even if it means you bite the dust. I call it the combat workhorse.
http://coriolis.io/outfit/viper/03C3B3C2D3A3D2C2727240p06002v420169.Iw1+kA==.CwBhrSo4g===
Have all the multi-cannons in one fire group and the beam in a different group. Use the single beam to bring down the shields and then open up with all mutlis. Multis work best at a range up to 1 Km. If the target is close to you, open up with multis and beam, if it is far just use the beam. Always target the power plant of ships of size Cobra or larger. Keep your target slightly below your nose to make sure the big multis underneath have a field of fire.
When making a jousting pass, thrust sideways with your thrusters. Your gimballed weapons will still be able to target the enemy and you avoid incoming fire.
To take down an Anaconda to get the shields down first fly backwards so that you keep a distance of just below 3 Km, thrust sideways with your thrusters, roll at the same time and keep your single beam on target. This way you can avoid the fire of the Anaconda. If you do need a breather, just increase the distance to a little over 3 Km which gets you out of range. As soon as the shields are down, get into the infight as fast as possible. Boost towards the Anaconda and use your thrusters to stay behind and slightly above or below the Anaconda, target power plant, 4 pips sys, 2 pips weapons and open up with all multis until the barrels glow.