Reccie advice: - Print off a map of the suburbs you like the look of, go online to realestate.com or similar site and put crosses on a few spots where you find the sort of house you'd like. This way when you get there you can check if the area measures up, or if all the reasonably priced houses are in a grotty area.
We found it much easier to get lost in Perth than Brisbane, for some reason, but after a few days you get used to it and work out your route beforehand, or just go with the flow and stop occasionally to figure out how to get back to the main road. We did both as I didn't want to have my head in a map and miss everything. You can also get a street index from the car hire company, which is helpful around the suburbs, or a GPS.
A camper would probably be cheaper as you area travelling quite widely, but we stayed in Perth city (Ocean Beach hotel - overpriced. Sundowner - North Beach - nice and friendly) and in Bunbury (Lighthouse Resort - very reasonable room rates with a view and restaurant) and when we accidentally turned up at the airport a day early we went back to the Comfort Hotel in Hay Street, which was fine).
Take an accommodation guide or print out a few options, as the accommodation we had booked for the first night was awful, and it's not easy looking for somewhere to stay in the dark, when you don't know where you're going.
Lastly, take time to do something fun even though you aren't on holiday. Although you're there on business, you can get jaded looking at houses and suburbs. If it's warm enough go swim at the beach, go hug koalas, take a river cruise or wine tour, go hunting for nightlife, or whatever. It all helps with the lasting impression.
. I guess we wold also be looking for similiar advice as well. We booked car hire through a travel agent... cannot remember who it is with but I could not get it any cheaper than they could ... so maybe worth checking with your travel agent. 
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