There can be a weird adjustment phase as your scalp gets used to the more gentle routine, but it shouldn't feel gummy (I've read this complaint from others about the Deva products). I would suggest keeping a low-poo on hand for removing buildup as needed (my current favorite is Shea Moisture Moisture Retention because it's the gentlest I've found so far).

As far as drugstore products, I've found I do best with a light conditioner for co-washing- my current favorite is VO5 Vanilla Mint Tea- it's a clarifying conditioner, so my roots don't feel heavy. I then use a richer conditioner on the length of my hair for my RO. Tresemme Naturals has a nice cone-free conditioner that works well (moisturizing formula). Some other good choices are GVP Conditioning Balm (available at Sally's- this is a very rich conditioner and might be too heavy for every single day), and Renpure Organics two new conditioners (Brazilian Keratin if you like protein or Argan Oil if you're protein sensitive)

Modified CG since 11/5/11
CLEANSE: CJ Daily Fix, DevaCare No-Poo, CHS Treatment Shampoo
RO: SS Caitlin's Conditioner, CJ Beauticurls Strengthening
LI: SS Repairing Protein Treatment, CHS Silk Leave-In
STYLE: Re:Coil, Curl Keeper, Deva Ultra Defining Gel, Curls Rock Amplifier,Sweet Curls Elixirs Okra Gel and Hard Hold Gel, SS Curl Enhancing Jelly and Firm Hold Gel