Abdominal surgery is major surgery and is painful, so make sure you come home w/ pain meds AND with a "pain plan" if/when those meds aren't effective (ie, does vet then recommend 1.5 doses of pain med or..?). Pain control is most important -- and DO give it even if he doesn't seem to be in pain...and give it on time or you won't stay ahead of the pain.
Your kiddo will do just GREAT - you'll be amazed how fast he snaps back. The first night can be rough as the anesthesia is still wearing off, so he may just want to sleep, and that's okay.
You may or may not need a cone...some dogs leave stuff alone and others don't. You could also try a onesie in place of a cone.
Keep us posted on how he does, we'd love an update!