By 'guides' I'm assuming it means the actual printed pattern for pinning to your selvages.
Vash's coat is essentially a full-length duster, right?
So if you want a base to start from and don't mind doing some modifications, try this one
(The Matrix dusters), using the A duster primarily. I'm using this same pattern for Kirito's (SAO) coat (with several panels modified or removed), so...lemme think...
If you vent the seams on EVERY panel from the hem up to the waistline, that should pretty much get the tattered effect of the one you linked. What the pattern doesn't have is are the buttons--it suggests velcro (ungh, no...), which you'll have to measure out and add yourself. The collar might need changed a bit, or you can just make a scarf (It's a scarf anyways, last i checked. It's been ages since I've watched Trigun).
That's the best advice I can offer. The Simplicity pattern is pretty close by default, and you can probably pick it up at your local Jo-Ann's (or other fabric store) for cheap. I got 3 copies of it for about $10US.