as above loads of advice but basically as far as filters go 2 options.
1. original airbox with performance panel filter (itg,k+n) all pretty much the same really down to personal preff.
2. maxogen sealed induction replaces the entire clio induction piping with its own box and filter, it is about 5 times more expensive though than replacing the panel filter.
as for mapping heard mixed reviews about superchips off the shelf map, some superchip dealers can tweak and adjust the map more to take into account breathing mods you have done, personally do a filter, then wait until you have done an exhaust system then contact rs tuning or one of the other tuners (k-tec/bb) for a group n map.