Recently had the same problem with my girlfriends car, she had the old wooden brown type with the button all but worn away, Bought a brand new silver fob from ebay, and just swapped over the internals, worth keeping an eye out on there. Otherwise get in touch with a proton dealership, they used the meta on the satria gti and they might be able to sell you one.

hope this helps

btw...paid £12 off ebay.

 

I have a Meta system on my car and I needed a new fob last year.
What I did was to contact my local radio dealer who gave me the phone number for Meta who subsequently sent me a new fob. (not wooden )
Chris