I've just spent a very productive morning at Neo Brothers Saab specialists (www.NeoBrothers.co.uk), chatting to Nicholas Neo and Nick Neo (father & son I believe), about whether their Maptun silicone hose kits for the 9-3 will fit the Z20NET engine. The whole lot of them (it's a large-family business, with Nicholas Snr and his brother being the owners) were very friendly and polite, and a sizeable crowd of them gathered around my engine, which they admitted was due to the novelty of seeing a Vauxhall in amongst all the Saabs.
After directly comparing their hose kit to the standard GM ones on my engine, the answer is Yes, they will fit. The majority of the hoses in the kit are identical length and shape to the Z20NET ones. One of the coolant ones is a slightly different shape, because the GM and Saab battery boxes (which the hose snakes alongside of) is a different shape, but the hose will still fit but will follow a slightly different route, but bypasses any obstacles.
The other hose that isn't an exact match is the large, curved one at the front of the engine. The Saab/silicone one is slightly shorter at the straight end, but it will fit if the plastic tube that it connects to is swapped for the Saab version, as this one is longer. This plastic tube has a sensor on it, but it unbolts, so the existing sensor can be fitted onto the replacement/Saab tube. Nicholas has a supply of 2nd hand tubes available.
These kits are available from the Neo Brothers website (http://www.neobrothers.co.uk/perform...1195_1285.html) or from their eBay listings.