If you haven't already then look at this website - http://www.visitscotland.com/ which should give you some ideas and also has lists of accommodation. Don't worry about toilet facilities, most places in Scotland do have indoor ones nowadays so you don't need to nip behind a hedge at the foot of the garden anymore. No worries about privacy then. They also usually have bathtubs and washbasins and some even have showers. These have two taps (faucets), one for hot and one for cold water. Some may still have a shared bathroom but most have ensuites nowadays as well as tea/coffee making facilities in rooms.
Car rental companies have a variety of vehicle sizes and I am sure some will have Jeeps for hire if you want. Remember that many roads here are narrower and some have lots bends in them so you might be better with a European-type car which is more suited to cope with the different style of driving. They also use less petrol (gas) which at current prices varies between £1.05 and £1.15 a litre ($1.70-$1.86) compared with something like £0.45 in the US and is due another increase next January when VAT goes back up to 17.5%. Petrol is also more expensive in remoter areas of Scotland so fill up in cities when you can.