My wife and I will be traveling to Adelaide area next year as part of our four week trip to “OZ”.

Anyone have suggestions for small group tours for 2-3 days of Kangaroo Island? Our interest lies in seeing the scenery and wildlife of the island.

Also, any recommendations for hotels in the Adelaide area?

It is many years since we did the trip but we did it with Sealink, they operate the ferry ( local experts may have more recent information I am sure ) but they do packages including transfer by ferry, tour and guide and accommodation so it's easy, there are no doubt others,
http://www.sealink.com.au/coachtours.html

For accommodation, and this apllies most places in Australia there are a lot of 'serviced apartment' type hotels, as a family they suit us but also good for couples if you like having more space and most often a kitchen or kitchenette, they are like hotels, you get more room though.

There are plenty of good hotels, I honestly can't remember where we stayed but it was 'serviced apartment' style which we always go for when we can.

Medina Grand Treasury Apartments are superb and well situated

You may want to check out Exceptional Kangaroo Island---they were called Adventure Charters. We used them a few years ago and highly recommend! We did the 2 day tour and it was hands-down our favorite leg of our last trip!!

You could try www.waywardbus.com.au and posted this for another:
I'd contact http://www.gsr.com.au/our-trains/ind...he-journey.php re how far ahead they suggest booking and though you are thinking of going all the way through to Sydney, have you thought of stopping at Adelaide and then tour to Melbourne via the coast/grampians/GOR and even take the ferry Queenscliff to Sorrento for last bit via Mornington Peninsula.
Adelaide - Wineries in Adelaide Hills extending down Fluerieu Peninsula, http://www.tourkangarooisland.com.au/ and
Victor Harbour
Melbourne - Botanical Gardens and many more - http://www.parkweb.vic.gov.au/ , the city itself, Dandenong ranges, Phillip Island for fairy penguins, Koalas and Wilsons Promontary for some great walks and more wildlife, there being companies like www.waywardbus.com.au , http://www.bunyiptours.com/ and http://www.wildlifetours.com.au/ that offer alternatives to city to city travel and also for day tours to places that may interest you.

Tasmania - http://www.parks.tas.gov.au/?base=1315 to get you on the planning way.

If you're looking for more info down south.

Pelham, it depends on budget and travel style really and you don't say what they are. Options exist at both ends of the spectrum - middle ground for tours is sometimes harder - for accommo it really is all about price and desired level of luxury or otherwise.

I went to KI with Campwild (now part of Groovy Grape I see) - saw loads - great trip - but a bit rough and ready. May not be what you are looking for.

Cheers.