Hi Hemamda
It's true that some of the planes in Indonesia - particularly between Bali and Lombok - are a bit dodgy, but I can assure you that the slow ferry if much worse. It is not so much a ferry as an old barge crammed full of trucks. One sunk a few years ago with a lot of lives lost. No one knows how many as there is no manifest.
I have flown countless times. The flight takes about 20 minutes from Denpasar in Bali to Mataram in Lombok. The airports are both located near the main tourist areas. Currently flight costs are around Rp 390,000 to Rp 450,000 (GBP 23 to 29) one way. If you fly, then you get a taxi to Bangsal harbour (about Rp100,000) and get a small boat over to Gili T (about Rp 40,000).
There are a couple of fast boat options. Both are about double the price of flying. One is called Gili Cat and runs for Padang Bai in Bali (around 2 hours from Denpasar) to Gili T. The other is Blue Water Safari which runs from Benoa in Bali (about 1 hour from Denpasar) to Gili T. These boats take around 1.5 hours to do the crossing - longer in high seas or stong winds. You should try contacting these companies and checking on the schedule and price if you don't want to fly. I think they leave Bali around 8am in the morning.
I'm pretty sure both these boats are currently in operation as I saw them advertised in the Lombok Times last week.
Cheers