I've never noticed the jitter/wobble to be any different between small, medium and large beam lasers. I rarely bother with more than grade 3 long range up to about 4.8km since you don't hit anything but it the biggest ships much above 4 to 4.5km range.
A large and two medium is a good combination. A huge and two small also good on an Anaconda consider the hardpoint placement.
The huge kind of cries out for a multi cannon, but I want my multi cannons on top of the ship so they can track and lead targets in my field of view.