Direct to the hotel from where?

As far as I know you can't get a taxi from outside Lantau Island to Silvermine Bay (taxis in HK are divided into 3 zones and there are strong limitations on travel outside the zones); moreover, the hotel there is 3* at best I believe. The hotel at the airport (Regal) is much better and just as convenient for the Buddha: you can get a taxi from either the airport or Silvermine Bay to/from the Buddha for about HK$120-150 in about 30 mins I would guess.

The logistics of luggage etc. seem a nightmare to do it the way you suggest. If I were you I would go to the Regal Airport hotel for the night before. Then put what you need for the day in your carry-on and check in at the airport (the hotel is attached to the terminal) before taking a taxi to the Buddha. You need to take one of the pale blue Lantau taxis, not one of the red ones. Then you don't have to pay for the taxi to hang around with your luggage and you can simply get another taxi back from the Buddha when you are done. If you want to go really light to the buddha then you can leave your carry on with the concierge at the Regal when you check out.