I am not fully ready for 750 yet, but I have tossed together a 500 list; the thought process involved tossing together 3 lists that embodied certain styles, and picking the best.
I have settle on a semi-static list with a small line of Kroot, 4 Crisis Suits, and a mobile scoring unit. Meltaguns are held in back; I'll have trouble against guntanks that sit in back, but I can bear the shots or deespstrike.
60pts: 6 Fire Warriors w/ Rifles
85pts: Devilfish w/ D. Pods
91pts: 13x Kroot
88pts: Shas’el Deathforge (TL-MP, FB) w/ HWBSF, HWMT
124pts: 2 Fireknives (PR, MP, MT)
55pts Deathforge (TL-MP, FB)