I guess I dont see what it is you think cones/sulphates would change?
I have an all drugstore product regimen, if that's part of what bugs you! There are CG products in stores, they just aren't labeled as such.
If you want to keep your curls, consider not only a shorter length, but also some layers. They would lighten the weight and put some volume back in. They also can help with drying time.
Unless you are planning to start straightening, there's not a lot you can do. I don't think anything will loosen your curls, though you can adjust you technique to pull them out some while styling.
But if low-maintenance is what you are going for, the best suggestion I have is short (BSL at most) and layers.
2c/3a/3b, Fine/med, Dense, high porous, & normal elas.
Lo-poo - Renpure Keratin, SMR, Giovanni SaS
clarifying - mix Johnson's H2T with low poo
Co-wash - Suave Nats. clar. or coco.
RO - GVPCB, Ion Eff. Care, TN.
LI - SMR, Cure Care, or RO
Seal - MO or Jojoba
DT - + honey, ACV, & EVOO to SM masque & GVPCB
PT - Gelatin!, CNPF
Styling - FSG, AIF, BRHG, LALS/PS, GF curl spray gel, SM Souffle/Smoothie, LOOB
Oils - MO!, EVOO, jojoba, GSO, SM Elixer, EVCO, VO5 Hairdressing