Personally keep the range implant on Surge. What u need for Eclipse are EM Rifles

My preference: Twin Miniguns (16+8) and juiced up cloak run speed. Your turning radius on an Eclipse while cloaking is insane, and you can destroy an entire FFA field easily if you use the terrain to your advantage.

Nades are tricky at best. Missile racks are a decent option just depends on the make up of the rest of your team.

Have you tried using a BLUE implant for Arc Range on the Eclipse? A yellow range implant at rank 5 is 55% bonus and rank 6 blue is 54% range, which is practically the same.

The gold ArcTorrent Range implant adds a few meters on the blue implant, which is helpful but not a must-have. Many players like me don't have the gold implant and it's not a big deal.

A bunch of my classmates run maxed Eclipses and generally the best weapons to try on it are EMRs, ArcTorrents, Disc Launchers and Miniguns. Nade Launchers also work well if you get in close and use them like shotguns. Missile Racks are decent too. Just be aware that Eclipse's big vulnerability is enemy Discs, so weapons that require you to get within DL range expose you to that risk. Still several close-up weapons are  popular, particularly ArcTorrents.

You probably don't have access to them but I run Cryo Javs on mine. Stealth, hit them with the cryo javs, run away. It works great on those heavy hitters because they don't move fast to begin with and the cryos make them stand still.

Eclipse is a beast but anything that makes you put yourself in line of sight is a risk. I'm thinking about upgrading my Eclipse to the next level so I can slap some minigun 8s on it (since I randomly pulled a gold minigun dmg implant) but I haven't pulled that trigger yet.