Effect Spore's chance of a random status is pretty thoroughly outclassed by a solid sleep move. The problem with Ingrain is basically that, despite pretty great recovery, it's likely that the opponent will have something that can hit you hard and be able to mess with you before you're boosted enough. Even with Spore, they just sacrifice something to sleep, then proceed to mess you up.
Growth/Sub/Spore with Regenerate isn't a bad start, though. Then your attack is the real question, since there's the chance a Sap Sipper will force you out (the other problem with your initial set). HP Ice, Payback, or even Rollout would all be options, hilariously enough, despite lacking STAB/recovery (a decent special attack type, a powerful hit to any Psychics coming in to nail you, and a Rock move to destroy Fire types and just about everything eventually).
And Black Sludge/Lefties for the item, depending on your preference.