2007 Holden Other Check Engine Light

Hello, the check engine light came on, on the dash last week, I took it to the mechanic who advised that the transmission needed to be serviced, I took it to Automatic Trans place and they ran a scan on my car, It came back with a code saying P0717, Speed sensor, no signal. I then took it to another Auto Trans mechanic for a second opinion, who said that it didn't come up with any code! But to diagnose it He would have to take the gear box and some other stuff had to come out so he could get to the sensor, which is at the back of the gear box! Estimated cost just to look to see if it is the sensor or fuse is about $1100.00. Then I was told that its probably the gear box, no sorry the clutch! Which one is it, I still don't know. When driving the car and the gears are changing, you can feel a shunting, like its bunny hopping from 1st, 2nd all other gear changes seem fine. Can some one help, does this sound right? Any help with this would be muchly appreciated. Can you recommend somewhere, where I can take my car to get fixed or just looked at on Gold Coast, or Brisbane, I'm new to Australia and I don't know any reputable mechanical repair places.

Thank you in advance Shelly