ill be honest with you, for a normal setup, the biggest thing will be the box, the box can make the best subs sound like **** and some crappy subs sound amazing, lol, but as far as consumer subs and what works, there are many options, and many very affordable options, for example, i have some Skar audio stuff in my 3/4 ton right now, subs, amp, and box, that stuff has surprised me and it was less than $300 for it all
my neighbors truck i just threw together a system for him with a kenwood 800w amp, a under seat box and some kicker shallow mount 10s and it sounds great, like i said for normal consumer stuff there are tons of options and it to sound good, just make sure what you get fits the airspace of the box, and the amp matches the subs, wattage and ohms and you will be pretty good