Swaddle vs sleep sack

My son is 6 months and still sleeps with me in a chair at night (ebf and I'm worried I'll fall asleep feeding him in bed). We are down to 1-2 feedings a night and is like to try putting him next to me in his bassinet. He can roll and push up, so I'm trying to decide between arms out swaddle or a sleep sack. He either sleeps on his side/back (roll away after unlatching) or he fusses until he's on his tummy on my chest. He sleeps in footie pajamas most nights. Would a swaddle feel more like me holding him or should we just go to the sleep sack?

Clarification: I am deciding between an ARMS OUT swaddle (velcro the belly area) and a sleep sack.