Special thanks to Ercüment Kasalar from the great band, Tephra, and also Bassart Custom Guitars in Germany.
They custom built an amazing guitar for Josh as you can see in the photo (left Josh, right Ercüment).

Specs are:
Body : 1 pc. Mahagony
Neck: 1 pc Mahagony
Fretboard Ebony 22 Frets / gibson – scale
Sustainer Pickup with Harmonic / normal Mode
Häussel Tozz Xl Hum Pickup in Bridge position
CTS 500K Master Volume / Tone
3 Way PU Switch
Transparent Black Nitro finish

Check out their sites:
Bassart Guitars
Bassart Guitars Myspace