I also posted this on your thread on BTF, which I know you read but this is for anyone else
If you are going to the Gili from Bali then the faster option is by fast boat. The ticket on the fast boat is about double the cost of flying (around Rp 660,000 one way). However, if you add up the cost of
1. travel to airport (fast boat often have free pickup in Bali) est Rp 80,000
2. travel from Lombok airport to Gili est. 150,000
3. airfare to Lombok + 30,000 departure tax, est 330,000
you will find that the cost of the boat transfer vs flying with the add-ons is getting pretty close (est 560,000 vs 660,000). Then weight it up against the time you waste with all the transfers, and the fast boat starts to look attractive. (you will be at the Gili by 10:30 am vs maybe mid afternoon if you fly).
There are fast boat services from Benoa and Padang Bai. Both take about the same amount of time ex Kuta Bali. The Benoa harbour is closer, but the water part of the journey is about an hour longer. My preference is Padang Bai as the water part of the journey is shorter, and less rough. It is about an hour or 1.5 hours from Kuta to Padang Bai. Someone like Gili Cat are good operators.
However for anyone considering going to the Gili around Christmas through to Feb/March, I do not recommend the fast boat due to very rough seas at that time of year. I would only ever fly then.