Schaz, we would like to welcome you to Sri Lanka, and hear more about Oman.
You are welcome to use our vehicle, or one of our friend's vehicles for self-driving your way around Sri Lanka, and we expect to charge you only about $40-50 per day, to cover costs only.
Please let me know if you prefer Automatic or Manual gears. Please bring an International Driving License, though you will probably not need it.
Getting around Sri Lanka by car is no problem at all, roads are fairly decent, and all places are accessible within a day's drive. But it really helps if you have some experience driving in other neighboring countries like India, Pakistan, etc., because drivers are definately not as well behaved and law abiding as in Dubai, and I expect, Oman!
Cost of fuel in Sri Lanka is presently under US$ 1 per litre.
There are basically no "don'ts" in Sri Lanka, except be careful making new friends with local "touts" on the beaches, and getting into non-metered "tuk-tuks" which we wont imagine you will need to do.
The rest we can fill you in about when we hopefully meet, please try to make your first day or two at Negombo Beach, a very nice beach resort area, close to the Airport, so our families can meet, we too, have a 4 year old!
Waiting to hear from you, with regards, Sam & Sheena.