Anyone shed some light on compatible springs/coilies? 1.4mpi

Hey guys, i know that certain sets of lowering springs or coilies will fit my car but ive never been certain, does anyone know the full list of which sets for which cars will fit mine?

For example someone told me that the polo 9n3 coilover kits will fit and work on mine no problem and the lowering spring sets will work provided i go for the same size engine as what mine has (for weight purposes)? is this somewhat correct?

So what else will fit it and wheres the best place to look for buying them? 

Im looking to lower it a bit but not slam it completely on the ground if that makes sense, im also on a budget so no racing spec stuff or air ride for me! :L