I think that both are good cameras, will be able to do what you want.
As far I know the shen hao has got the bag bellows and has got graflox back for roll film holders. The tachi is lighter, but has no graflox back and seems like it's way harder to go wider than 90mm. Though if I'm not wrong, it's got a fresnel lens for the ground glass viewing.
No experience with both, just what I heard about them.
I have the Shen Hao, it's a good camera, I recently weighted it, 5.5 lbs, and there ought to be a law against short bellows and single extension 4x5 field cameras.
Look for a good, used Zone VI field camera. Weighs 5.5 lbs., sturdy, 18" of bellows. If you use wide angle lenses, look for the accessory bag bellows. Used price is usually in the $600-$800 range.