Hi,
There have been quite a few threads on here about transport options from French airports to Disneyland if you scroll through the topics.
The TGV is not necessarily quicker when you look at the whole time taken from your arrival terminal to your hotel.
A private transfer can take 25 - 50 mins depending on traffic door to door. A few recommended companies are listed on the Trip Advisor Disneyland Paris forum, that posters regularly use. You do not pay in advance - pay the driver at the end of each journey. Some give a discount if you book both ways, so can cost ? 120 in total for 4 persons.
If you decide to take a taxi, agree the price first, as some people have been charged over ? 100 one way. A private transfer is the agreed price no matter how long it takes. The driver will be waiting for you in arrivals, holding a name board, with the vehicle parked just outside usually.
They will also have correct child seats if you give kids ages when booking, and some have DVD players with Disney movies.
The Disney VEA bus would cost you ? 51, but will take longer and may not stop at the Associated hotels like yours. You may have to get off at the bus stops by Chessy railway station, then catch the free shuttle bus to Dream Castle. It depends on what time your flight arrives.