i have a full exhaust system for a 1.3, standard except for the rear box. it's not all that, granted. made by ernst, from gsf. sounds pretty roary if you push your car a bit. yours for £40 (also got a twin DTM back box from an 8v GTI) will fit the same exhaust as i had to use a "step up" tube to fit the ernst one properly. ernst is twin 80mm round, certainly looks the part and it kept me happy till 16 valves came along! let me know!
as for lowering, depends on how good you want it? i may have a set of 60mm lowering springs, i ran em on mine for a year, harsh ride with standard shocks but gives the desired effect!