i posted thread on audio section but no one seems to go there anymore

I just looked pioneer champion series two 10" subs and mtx mono amps. just want to hear some opinions and advises. I have never had sound system but this guy i talked today told me pioneer subs are the best and bla bla bla.
AND, i've always heard aftermarket HU would make sound better when adding sound system. i think it was becuz more ohms but i have no idea. educate me plz!