How to ask some to watch our kids for our wedding.

So here's a semi-quick synapse. My FH and I recently got engaged but we all already have 4 kids. He had a 'pre-started' family with a beautiful 8yr old daughter and we have had 3 sons(twins 1yr old and toddler 2yr old). Our families are not local, so we will likely end up with a destination wedding to have everyone meet in the middle, so to speak. Our biggest concern, is what are we to do with our kids on our wedding night and day after. That is all the time we are asking for alone time. The things is we don't really know what/how to ask 'distant' family to watch our children so we can have some alone time. Should we just hire a sitter? What are some suggestions if no one has really stepped up and offered to help in this area?