C.B.
Considering the kids' ages, you might want to have a family getaway, not the traditional honeymoon. Make it a real special place tho.
I'd opt for the large gathering later. More people to celebrate with. plus if you're watching your budget, having two parties could put a strain on it, and stress you out twice. Once would be enough.
Lastly, don't register for gifts. I'd wait and take an inventory of what you two could use, after his and your stuff kinda comes together. what does he have, you have, not have, need. Then use the $$ from one of the two parties you'd consider and put it towards that.
Congratulations, tho!