SANParks.org Forums

Unless you are flying with Emirates you will have to fly in to Joburg or Cape Town.
You can fly to Durban or Cape Town or Port Elizabeth or use the Baz Bus.
A hired car between 4 of you will give you freedom of movement and a place to store your luggage. You could try to get a toyota corolla which has a large boot.
If you are all below the age of 40, then the Baz bus is a good option as it travels along the coast and you will meet up with young people who will tell you about their trips.
They often stay at backpackers accommodation or hostels and the Baz bus goes to these places. See their web site.
The Baz bus- fare between Dbn and Cape Town is R2500 about 250 Euro each. (its usually cheaper to fly)
A car for 10 days at R400 a day, R4000 and fuel at R10 a litre, say 100 litres, another R1000. Just a rough idea!
The Addo game reserve is close to Port Elizabeth and a shuttle service connects to take you there.
If you are new to exploring S.A. and don't have time to research it then Baz Bus is the easy way!

If taking the Baz-bas, Are there any stops close to the SANparks?

Emi the Sanparks are scattered all over South Africa. But I think the bus passes the storms river and you can be dropped off there. and of course if you get to Cape Town there is the table mountain national park .. But as I have already said you need transport in the Parks . Unfortunaltey due to the dangerous game in the Parks you cannot just walk into them . there are a few exeptions Baz bus will be expensive for 4 people much cheaper by hired car and then you can stop off whenever you want to.

Baz bus has a "4 day wildlife safari" to Kruger park which is a South African National Park (sanpark).
There are private shuttles and tours that link with Baz bus and their hostels to get to Addo park. (also a sanpark)
Lonely planet and tripadviser and sanpark websites give clues. Also spend time on baz bus site.
You will have to do research. Good luck and enjoy!