I found this.
For people looking for replacement rear shocks for the GT LTS-2 (and STS...) it might be possible to use shocks from this manufacturer, who custom build coil over shocks to order: http://www.yasusu.com/
Yasusu have a shock catalogue ("DM for Bike") and measurement and setup instructions for download at this link: http://www.yasusu.com/ser.htm
Here's some info here on MTBR giving user perspectives on Yasusu shocks: http://forums.mtbr.com/showthread.php?t=505631 http://forums.mtbr.com/showthread.php?t=527991 http://forums.mtbr.com/showthread.php?p=7102481
You can get these shocks via eBay (locate the seller "i-sports-tw" and search the seller's store for "shock")
or place an order directly with Yasusu.
They make the shock and the bushings to order. You'll need to specify the shock and bushings in metric.
Note also that I e-mailed both Yasusu (with a technical query) and the ebay seller and this revealed that the ebay seller is a Taiwanese agent, selling the shocks on behalf of Yasusu. Therefore, if you place an order you will need to be very clear with your dimensions since English is not their first language and they are not intimate with the shocks. I was asking questions about the disparities between info in Yasusu's catalogue and the ebay advert for a shock and they ultimately admitted that their ebay advert was wrong. The catalogue was correct. Ebay lists the one I was looking at as BNCP 501, when it actually is a BRNP 501. Their ID convention is:
N = No rebound adjust / R = Rebound Adjust
C = Compression adjust / N = No compression adjust
P = Preload adjust
I hope this helps!
(Note - I am not affiliated to Yasusu, I had been looking at them as an upgrade for a Mongoose Blackcomb and when I saw that people were having trouble getting a replacement shocks then I though that this might be an option)