Thank for all the tips and suggestions. We actually ended up deciding to try and save some money and go lap child.

We're booked SFO-MCO (Disneyworld here we come )

Any thoughts on bulkhead vs. standard row? Both outbound/return are on an A320. I booked row 6 (ABC) on the way out. My thought is that we might be able to put the 4MO on floor by the bulkhead to let him crawl around a bit. However, my concern is that the the armrests dont go up on the seat. Will that make it too uncomfortable when the child is in the "lap"?

Lastly, thoughts on booking AC D (not in bulkhead) and hoping B stays empty e.g. obviously trying to get 4 seats? And if B gets booked ask D and B to switch?