The hotels near Disneyland are limited and the price is very very expensive, so i suggest you stay at a hotel in downtown area, you may take the public transportation in Hongkong, it is very convenient..I can recommend some hotels to you, such as Kowloon Hotel, Harbour Plaza Metropolis, Harbour Plaza Hong Kong or The Knutsford Swiss-Belhotel..this is just my suggestion..:)
By the way, the weather in Hongkong in March are very pleasant and comfortable. Have fun...