Sir without confusing you more by using jargons, let me give you an example, driving an Audi A4, Accord and a Mehran all @ 60km/hr, can the experience be same.
You can substitute Pioneer D series, Alpine Type S and your stock speakers in the above example and solve the equation.
Adding to that all the power and loudness distorts SQ, like what more brightness or sharpness does to photography, that is why all SQ stuff is focused on built and material, rather then power.
That is why a 100$ driver can outmatch the 5,000$ one in power.
For Components, Pioneer D series are best in tonal accuracy, hands down, while Alpine can go very low and are much more efficient (can get comparatively more loud without AMP).
Kenwood S series is also very good, listened to it in enerlevel's (kevin dada) car.
Kenwood - KFC-S703P
I have not quoted any AMP because you like to listen at low levels, else no good sound system is complete without an AMP or SUB wether its a 100$ ICE system or a 5,000$ Pro Audio Home theatre, and there is no substitute to both of them, but both AMP and SUB needs space and electrical upgrades and also more money so its up to you.
Pioneer 6050UB is just a waste of money, no better then the Alpine CDA105 or Pioneer 5250SD, Alpine is way better if you can source one in Lahore, else the Pioneer 5250SD has a much better sound and AMP gain.
The only good 2 DIN was that 5000MP that used to come in the old Altis, if you have space or can settle without USB or AUX.
FH-P5000MP
You can go for these AMP for around 8-9K Rs, all are good:
JVC Mobile Entertainment \ 4 Channel Amplifier - KS-AX4504 \ Introduction
JBL - GT5-A604E - 640-Watt 4-Channel Power Amplifier
Kenwood - KAC-9405
XM-GTX6040 : Xplod Amplifier : In-Car Entertainment : Sony Middle East & Africa
For Rear 6 X 9, Alpine Type R and JBL Power series are good, will cost you 8-10K Rs but they can blow Kenwood 718, even 718ex out of water, with or without AMP, watch out for JBL fakes and China copy.
JBL - P963 - 160mm x 229mm (6" x 9") 3-Way Loudspeaker
Alpine Electronics of America, Inc.
I do not like wooden enclosures because they will ruin your car's look, you should use 6 X 9 brackets to strengthen the rear panel.
Hope I have cleared out some things.
Regards