Magkano budget? and ano ba gusto mong maging overall setup ng oto? would you upgrade subs in the future? kasi sayang lng pera bro if 2-3 mos mag u-upgrade ka din, try deciding what you really like (SQ, Loud and Clear, SPL etc.) then you can start from there, if SQ I suggest invest muna sa magandang Speakers, preferably seps, not coax (integreated 2-way, 3-way), if gusto mo lng tlga may konting bump from bass I guess NBN would do, or ipon pa konti and get a 8" or 10" subs, seal mo nalng, a V12 4-channel amp, channel 1 & 2 can drive all of your seps, 3 & 4 bridge mo for the subs.