Yes, yes, yes, yes, yes, yes, yes,
Especially since you have multiple pets of your own. I always require a M&G prior to accepting any booking because I need to make sure our pets get along and I want to see how they behave in my home. A dog who walks in and starts marking all over my furniture, for example, is not going to stay with me.
In the case of two dogs who have never been boarded, if this booking is for a lengthy stay, I might propose doing a test run first of say one night or a doggy day care of one day, just to see how they acclimate to you and your home environment.
M&Gs are highly advisable. I can't tell you the number of sitters posting her with horror stories and the one common reason is that they never met the dog or owner before the stay. If there is still time, have the M&G and really discuss their boarding needs. Also be sure that you have an emergency contact in case the dogs need to be picked up earlier.