Any1 knows about ebm/industrial bands which are very similar to Skinny Puppy's sound but they aren't vocal? or at least, they aren't sung.

Something similar also to the song by Sisterhood (Sisters of Mercy) called "Red Finland Egypt White" or so.

Hmm, off the top of my head... how 'bout

Xorcist (mostly instrumental, very puppyish sound)
A Split Second (a few more vocals, lots of thumping bass/percussion)
Front Line Assembly (their earlier stuff is very sample-heavy, no guitars, just keyboards/samplers)

Other than that, some other obscure (and not-so-obscure) stuff you might enjoy would be Borghesia, Industrial Artz, Young Gods, DAF, Bigod 20 (and other F242 side projects), maybe some Laibach, Wumpscut, etc...

Post up what you're enjoying.  There are a lot of industrial bands that are almost clones of each other, and I certainly don't know 'em all either.

It's hard to find "Industrial" bands with no vocals at all.  A lot of them are at their best doing instrumentals, though.  I always found Skinny Puppy's music far better than their lyrics/vocals.  Check out the Skinny Puppy side-project from c. 1989, "Doubting Thomas," that's basically Puppy without Ogre.  Also check out the Tear Garden albums, which are collaborations between members of Skinny Puppy and The Legendary Pink Dots.  If I can lead people to Legendary Pink Dots, I'm always happy.
An artist who never used vocals was the late Muslimgauze.  His music was an amalgam of Middle Eastern music, electronica, sound collage, and noise distortion.  He put out about 100 releases from 1982 to his sudden death in 1999.
I also recommend the French Industrial "fetish" band Die Form (pronounced Dee-Form)
Don't forget Coil.  One of my favorites.  They no longer exist since John Balance died in an accident a coule of years ago.  Einsturzende Neubauten, Current 93, and Nurse with Wound are all extremely interesting.  All these groups work with a much more diverse sound palate thatn Skinny Puppy, but Puppy has often been a good stepping-off point to more adventurous music.
I would peruse the Metropolis records catalogue:
http://www.metropolis-records.com/
The Soleilmoon catalgue, which distrutes for dozens of smaller Industrial/Ambient/Experimental labels worldwide:
http://www.soleilmoon.com/
Also the label for the late Muslimgauze:
http://pretentious.net/Muslimgauze/
Brainwashed handles a lot of interesting stuff, including Legendary Pink Dots:
http://brainwashed.com/
Now, Subconscious Studios handles Skinny Puppy and side projects.  Puppy spawned a lot of instrumental side projects you would definitely like, including the "solo" released from cEvin Key, which are top notch!
http://www.subconsciousstudios.com/

Thanks a lot for all the info mates. Appreciated.

I will look up your posts when I have more time to get all your generous information.  :) 8)