Agreed, My Honda vision has more power than a 1.3 mk2. Slowest thing with wheels. Webber should give it an extra -5 horsepower. Put some cheapo G-max lowering springs on it, and some freebie 185x65 14inch Driver steelies off someone on the forum on it. Will give you far more fun and driving pleasure then any engine mod on a 1.3. At least you can enjoy the excellent well balanced chasis and handling of a mk2 golf. Tidy it up, sell it for more then you paid, get a gti in a year or two.
If you want a list of what to do with a 1300, read this post which talks about a load of mods to 1300s: http://www.clubgti.com/forum/forum_posts.asp?TID=49143 I wouldn't recommend touching the engine. Relative gains aren't worth it. Make it handle instead.
Its worth it in the polo coupe S as it only weighs 750 and has 100 thingys of torque, does anyone know where to get a manifold to fit twin carbs ?