if you decide not to go custom exhaust you can get lucky and pick up a viggen cat back system. with so many viggens getting modified exhausts it shouldnt be extremely difficult to find someone selling it on ebay. i have the viggen cat back exhaust on my n/a 900 and it sounds real good
Next: smoked tail lights possibly...
Done: Viggen Cat-back exhaust, Custom 3\" Stainless Intake, Taliaferro Direct Intake Tube, Viggen Antenna, Custom Heat Shield, 17\" TSW Rims, Intrax Lowering Springs, MP Rear Sway Bar, Elkparts Eyelids, Custom Grille, Smoked Side Signals, Clear Corners, Debadged, SAAB Chrome License Plate Frame, SAAB Decals, Carbon Fibre Dash