On the note of camshafts, the Naturally aspirated 2.3L from the 94-98 900's has the most aggresive Saab "shortblock" camshaft. Assuming T7 is happy with it, it's good for 20-30 hp on a T7 car, and about 10-15 hp on a T5 car. And if you can find one and get it reconditioned, not expensive at all. Also I have seen dyno sheets of Viggens with just a chip. Very little hp increase, and maybe 15-20 lb ft more torque.
Nick Taliafferro from Taliafferro Saab put the B234R (9000 Aero, not as aggressive as the B234i camshaft from the Naturally Aspirated 2.3L) camshaft in his Viggen, and combined with a downpipe and intercooler (neither of which makes more than 1-2 hp, but drastically increases spool up) he got from about 210 whp, to 232 whp. Then by adding a chip he was up to 252 whp. If you got the naturally aspirated
camshaft you would see (assuming T7 likes it like I said) around 245 whp. Combine it with an exhaust and intercooler and you'd have a very mean machine that shouldn't void the warranty. (The dealer would need to prove that your mods hurt the engine. Exhausts and intercoolers are the only thing they would be able to spot. Neither of which could possibly be harmful to the engine, and the camshaft is nearly impossible to spot. After all it's a Saab cam.)
It's probably best just to get a stage III from MapTun or somebody similar. This is because intercoolers are generally expensive, and the stock Viggen IC responds well to high boost, but not high flow. Putting camshafts will give the engine too much flow for the IC to keep up with.
If you want to check out some relatively cheap intercoolers try www.bellintercoolers.com
.... they can make custom end tanks, and an intercooler easily capable of handling anything the Viggen can throw at it would be about $600 to get done custom. Which is about half the price of the SpeedParts and MapTun units, which are only about half the size. But the SP and MT units will be much much easier to instal. Anyway ... just my thoughts ... 213 whp rocks!