I prefer the M7A on the nose. It tracks well with the other lasers in the front meaning solid hitting bursts from all guns to take down the target fast. I've played most of the ICC missions (only getting blown up on the last one with the warden doing something stupid) and it can take a pounding.
As for buying stuff in voyager direct for real cash vs electronic access for REC....I would rent right now. Still too much balancing to go for me to commit to buying unless you are REALLY into Arena Commander and are playing it most days of the week. What you buy now will most certainly not be what you get at launch. If you are looking at outfitting a ship for when SC goes live, I would wait to see how things play out. If you are wanting to outfit a ship for arena commander and you have other uses for your REC you absolutely need...I would still not buy it, but it's a tougher call.
BTW, if your other uses for REC is renting the same ship over and over, you might be better off buying the ship when it goes on sale. If your REC is used to rent multiple ships to see what you like, that's different and most definitely a good use for your REC. Remember though, ships will also change between now and launch. I suspect 4.0 will be a good indicator of what ships will be like (in a year or two), but even then, I would expect multiple balancing passes on ships and weapons with the first pass being the major re-alignment and subsequent passes being smaller and smaller tweaks
