Vanilla CA

I'd say you shared wrong the army lists. As for the miniatures, you have a mix&match... Indeed, you can only play in generic because you don't have most of Onyx's good stuff: you need either the Rodok box or the Unidron SW box... and a Nexus as soon as they get out.

For generic you can use all what you have, but the Seed Soldier is something that sees little to no table outside the Shasvastii sectorial.

 

You actually have a nice collection of guys there in my opinion, the seed soldier for instance I would use as either a Malignos or Shrouded either as a proxy or through small conversions. Here are two lists I threw together, don't know if they are competitive but they look fun:
Combined Army
──────────────────────────────────────────────────

9
SOGARAT Lieutenant Feuerbach / Assault Pistol, AP CCW. (1.5 | 57)
RAKTORAK Red Fury / Pistol, Knife. (1 | 26)
ANATHEMATIC Hacker (EI Hacking Device) Plasma Rifle, Nanopulser / Pistol, Shock CCW. (0.5 | 88)
UNIDRON (Forward Observer) Plasma Carbine / Pistol, Electric Pulse. (0 | 15)
UNIDRON (Forward Observer) Plasma Carbine / Pistol, Electric Pulse. (0 | 15)
UNIDRON (Forward Observer) Plasma Carbine / Pistol, Electric Pulse. (0 | 15)
FRAACTA Boarding Shotgun, Nanopulser / Pistol, Knife. (0 | 28)
MAAKREP TRACKER HMG / Pistol, Knife. (1.5 | 33)
SHROUDED Boarding Shotgun, Antipersonnel Mines / Pistol, Knife. (0 | 23)

4.5 SWC | 300 Points

Open in Infinity Army

Combined Army
──────────────────────────────────────────────────

GROUP 1 7
MALIGNOS Hacker (EI Assault Hacking Device) Combi Rifle, Antipersonnel Mines / Pistol, Knife. (0.5 | 41)
MAAKREP TRACKER HMG / Pistol, Knife. (1.5 | 33)
UMBRA LEGATE Lieutenant K1 Combi Rifle, Flash Pulse / Pistol, DA CCW. (0.5 | 40)
MORAT Missile Launcher / Pistol, Knife. (1.5 | 19)
FRAACTA Boarding Shotgun, Nanopulser / Pistol, Knife. (0 | 28)
MORAT Paramedic (MediKit) Combi Rifle / Pistol, Knife. (0 | 16)
UMBRA SAMARITAN (EI Assault Hacking Device. UPGRADE: Goodnight) Plasma Carbine, Flash Pulse / Pistol, Vorpal CC Weapon. (0.5 | 43)

GROUP 2 4
UNIDRON (Forward Observer) Plasma Carbine / Pistol, Electric Pulse. (0 | 15)
UNIDRON (Forward Observer) Plasma Carbine / Pistol, Electric Pulse. (0 | 15)
UNIDRON (Forward Observer) Plasma Carbine / Pistol, Electric Pulse. (0 | 15)
RAKTORAK Red Fury / Pistol, Knife. (1 | 26)

5.5 SWC | 291 Points

Open in Infinity Army

 

You have an anathematic. Use it as your lieutenant. Even as a hacker he can duke it out with most other hackers and feel fine, and if he does buy the farm mnemonica keeps you from just plain dying. It's important to not waste him on some crazy play thinking he can rambo around unprotected, though.

4r
──────────────────────────────────────────────────

10 1
ANATHEMATIC Lieutenant Hacker (EI Hacking Device) Plasma Rifle, Nanopulser / Pistol, Shock CCW. (0.5 | 88)
SOGARAT AP HMG / Pistol, AP CCW. (2 | 56)
UMBRA LEGATE Hacker (Hacking Device Plus) Boarding Shotgun, Flash Pulse / Pistol, DA CCW. (0.5 | 43)
MORAT Paramedic (MediKit) Combi Rifle / Pistol, Knife. (0 | 16)
IKADRON (Baggage, Repeater) 2 Light Flamethrowers, Flash Pulse / Pistol, Electric Pulse. (0 | 9)
IKADRON (Baggage, Repeater) 2 Light Flamethrowers, Flash Pulse / Pistol, Electric Pulse. (0 | 9)
NOCTIFER Missile Launcher / Assault Pistol, Knife. (1.5 | 32)
MORAT (Forward Observer) Combi Rifle / Pistol, Knife. (0 | 15)
MORAT (Forward Observer) Combi Rifle / Pistol, Knife. (0 | 15)
KRAKOT RENEGADE 2 Submachine Guns, Chest Mine / Pistol, Shock CC Weapon. (0 | 17)

4.5 SWC | 300 Points

Open in Infinity Army

here's a list you can try. Proxy the Noctifer with the seed soldier, the ikadrons with the unidrons and the krakot with one of your vanguards. It has two models you can mnemonica in to either keep using the high WIP (the legate) or just make your LT sturdier (Sogarat), has goot data tracker options, specialists and so on.

As for what models you should consider buying next, I think support pack, drones, a charontid and daturazi are a good way to start expanding your stuff. Save the big guys like overdrons for later when you have a solid suport base.