@Sami - IMO components are useful when you have external amplification and elaborate crossovers and all that. If you plan to just use the HU's 4 speaker outputs, the usual coaxial speakers are more than enough - however with these you are restricted to a particular size because of fitting limitations. And size determines how well the speaker can reproduce low frequencies - larger ones are better.
Polk Audio db691 awsum sound quality of this model
and in front - Infinity Ref 6020 cs
and please buy these items and fits from a genuine dealer or from maruti showroom they will genuinly fit the speakers