Here's a build I put together yesterday after admitting to myself (again...) that the Orion just isn't a made for brawling. The weapons allow you to support from a distance melting armor with the 2x LLas or shredding it with the LRMs. I use the LRM5 to suppress and launch full volleys when I know they'll connect. I'm pretty new to LRMs but this combo seems to be effective so far. Machine guns are mostly an after thought but they have been useful especially if you're still around at the end of the match when mechs have exposed internals. The 2 tons required to use these can be swapped to upgrade the LRM10 to an LRM15 or AMS.
Not bad. I might have to try this one next. I would swap the LL's for ERLL's though especially with how much cooling this already has. I always use ERLL's and rarely overheat with my ON1-V. The longer range is worth it especially on the big, open maps.
ERLLas were initially intended to be equipped but I was out of funds and since then I haven't had the time to try it out with the ERs.
I'd move the 1st ton of LRM ammo from the RT to LT (or CT) for better crit padding, but that's a nitpick. You'll probably blow through the first ton far more quickly than your opponent can blow through your armor.