We will be traveling to Scotland in June with my parents and children. There will be 7 of us total plus luggage so we are thinking that renting a 9 passenger minibus would be the best option. Does anyone know a good reliable rental company that rents minibuses? Is it better to rent at the airport or away from the airport?
Glasgow airport has all the major car rental companies. I can't think of a reason not to rent at the airport as it is much more convenient than having to wrangle your luggage to another location. I think there's one rental company located off-premises that's a bit cheaper than the "name brand" companies, but I would say the hassle is not worth it, especially at the end of your trip when you just want to drop off your car and relax.
Do give yourself a day to get over jet lag before you do much driving, though. And, leaving Glasgow airport there are at least 2 roundabouts whose signage is (IMO) not self-explanatory. To make sure you get onto the Motorway in your desired direction, ask the rental agent about the signs and what to follow.
In British/Scottish English, the vehicle you want is likely to be called a "people carrier"; don't call it a van or you may end up with a delivery-style van w/no passenger windows.
Driving a relatively large vehicle on Scotland's narrow, winding country roads with rough stone walls often bordering the roadway will be a challenge, so when you plan your route allow plenty of time to pull off every so often to let faster cars pass you.
BTW there are hotels right at Glasgow airport, literally walking distance from the terminal. The Holiday Inn is terrific; Holiday Inn Express is OK but not as nice (as you'd expect since it's cheaper).
Given that a large vehicle will be both expensive and difficult to maneuver, look into the option of renting two smaller cars. This also gives you much more flexibility, if you want to split up for the day for any reason.
If you do want to take a day or two in Glasgow to get over jet lag before trying to drive, there's LOTS to see and do there; everyone in you group should find things of interest. Rick has an excellent chapter on Glasgow in his Scotland book. You could start with Rick's City Centre walk or a hop-on, hop-off bus.
In addition to the good information above , I would also suggest two cars , rather than one large multi passenger vehicle . I have done a substantial amount of driving in Scotland , and you cannot underestimate the challenges posed by narrow and winding country roads , a bus ( mini ) would complicate things greatly . Also be aware that getting a passenger car would be somewhat easier to obtain with an automatic transmission , ( manual transmissions are far more common overseas ) A larger vehicle , would be far more likely only with a stick shift . That would be a real problem if you have no prior experience driving one .
I don't know where you're planning to travel in Scotland, and I have never been there myself, but I wonder about the possibility of combining public transportation from city to city with one- or perhaps two-day private van tours. I think anything you can do to avoid driving yourself around in a van is worth considering because of the rural roads and parking difficulties in cities.
In addition, others have said that in Europe, renting a van (aka "people mover") can cost three times as much as renting a car, so I'm not sure that what I'm proposing would be more expensive than renting a minibus for the bulk of your trip, which would probably include days when you really don't need the vehicle.
I can see that this suggestion probably would be less useful if you are traveling with young children, though.
Any kind of vehicle will be a useless albatross in the cities ( Glasgow , Edinburgh ) but for exploring the countryside , a car is invaluable . It will get you to areas that are relatively inaccessible by public transportation , thus giving you far more usable time to actually see different places . As an example - While having landed in Fort William , the car made quick , direct work of driving out to see the Glenfinnan Viaduct and the memorial at the head of Loch Shiel . On the way back to Fort William , an easy stop to see Neptune's Staircase . Using a public bus would have killed time and limited flexibility waiting for scheduled connections . Another example is how easy a car made it to explore the half dozen or so fishing villages ( Anstruther , Crail , Pittenweem , et al ) strung out along The Forth going from St Andrews to Edinburgh . I could go on , but I'll leave it for now .