Meta weapons are ArcTorrents, Disc Launchers and above all EMR Rifles. Shotgun 8s too. Railgun is still viable but get EMRs instead.

Top meta mechs are Panther, Guardian, Surge, Stalker, Redeemer. Other meta mechs are Ares, Killshot, Orion, and Tengu. Bastion and Gatecrasher are also seemingly meta but they are still new and I'm not quite sure what the verdict is on them.

Overall your hangar looks good and economical  as a early/mid-game transition hangar. I'd focus on replacing Juggernaut (too slow) and Shadow (too frail, esp b/c of enemy Disc Launchers). I'd recommend Stalker and Surge as replacements. Missile Rack 8s are a good weapons thru mid-game but don't take the past Rank 5. PC8s are a cost effective weapon for now as Carbines aren't worth it, but you are going to want Arcs and more DLs, focusing on 12 and 16 EN. The big thing would be to get rid of the beams and replace them with EMRs. The Longarms can hold their own for a while but will eventually need replacing. Jav6 can also stay relevant for a bit but don't bother with other 6EN weapons.