Kevin2008...
First of all...Congrats on your new babies..the 5 month old
and the soon to be built SFT!
May I also congratulate you on finding iRV2...I feel this is the friendliest and most helpful RV site on the web.
You will find seatbelts under both front sofas. As far as putting the seatbelts in the dinette... there could be a safety issue involved with the refrigerator being so tall AND running with a propane line to it.
Have you actually verified that the childseat facing to the side is an issue...or if it is an issue in an RV as long as the child is NOT facing front?
The other option..what about removing the smaller sofa and putting a special made small j-lounge with seat belt attached on the small J side?

Good luck with your dilemma...
OK...another thing... If you would like to have "Monaco Owners Forum Member" under your display name to the left...just say "Karma Please" and you'll be in!!
Again..welcome to iRV2 ...please vist & post often...

MM
PS.. I love our SFT!!