Forest River Salem quad bunkhouseI would suggest this floorplan.
I realize that it is larger than what you are wanting, but....
1. With 6 people, 25' is going to be really small really quick. The kids are NOT going to stay the same size they are now. They will grow and they will want their own bed because they no longer fit in a full size bed together.
2. You will need seating space for the kids if it starts raining or in the evening to play cards or board games.
You might even want to look at a toy hauler.
If you don't have a "toy" in there, there are usually 2 couches to be used during the day that turn into beds in the evenings. It also has a door that can be closed so you don't have to listen to them ALL the time.
Now, used vs new. You might want to do some research on here before you purchase new because you may have a 1 or sometimes a 2 year warranty, but....it may take several campers before you find what really works for you. If you purchase new, YOU take a big hit in the depreciation market. If you purchase slightly used, someone else has taken that hit. Just something to consider. It might pay you to purchased a used vehicle, but to hire a RV technician to check it out for you. Just look through these forums about all the problems that are being reported on new RVs. Being new definitely doesn't mean it's going to be trouble-free, but the price will be covered for a year.
Almost every manufacturer has a bunkhouse, a toy hauler and "whatever". Find a dealer that you like and check out their reviews for follow-up repairs and go with their line. You will be glad that you did.
2017 Ford F350 Crew Cab 6.7L 4x4 DRW