Black Market Pipeline Quality could lower the price of your 'ware by 10%.
Biocompatibility can help with keeping essence costs in check without paying for higher grade 'ware. (Type-O system does that even better, but you'll probably not have the quality BP free to get it.)
Already using Biocompatibility; still need Alpha. Also, I thought Type-O only worked with Bioware?
EDIT: Are there any mods other than "Customized [ATTRIBUTE]" that can't be added/upgraded after c.gen? Because, if not, I think I've got it licked; he'll just be lacking most of the extra Armor, spurs, etc.
EDIT REDUX: Okay, the way Chummer is showing things stacking suggests that Encumbrance Penalties only affect the "real" stats, not the averaged total score with cyber limbs. Is this accurate, or a bug with Chummer?