ok, continuing my very slow quest, just bough a pair of component speakers and a pair of subs and have $500 left for amplification, do I

a) power the speakers with the head unit and spend $500 on a sub amp
b)spend the $500 on a 4 channel amp to power speakers and subs
c) buy both an inexpensive 2 channel amp and sub amp

one last thing, my deck only has 2 pre outs, will that work for my small rig or do I need to upgrade to a deck with 3 pre outs?

I would go with a) What components ans subs do you have? Spend the whole $500 on a sub amp now. Then save up and get a good 2ch for the fronts and you're done. You can use the rear preouts for the sub, run fronts off the deck for now. This allows you to get better stuff than trying to get it all at once.

d) tell us what you have for a sub and components so a number of good options can be chosen.

pair of 10" JL Audio W1's, pair of JL Audio VR525-CSi 5.25" component speakers, and a discontinued Alpine deck

And yet more info needed......what is the voice coil arrangement of the subs?10W1V2-4 or 10W1V2-8.

10W1V2-4 but I can exchange them for 10W1V2-8 if that makes a difference

Get a four channel amp to start............. bridge two channels for the subs.......... and the other two channels for the components. Later on, you can then run the components actively all off the four channel and add a sub amp to the mix.

IMO, I would go for a Sundown Audio SAX-100.4, bridge the back 2 channels for the subs (About 350 watts rms at 4 ohms) and use the other 2 channels for the front speakers. Then one the inevitiable happens and you want more bass, you use the 100.4 to go active on the front speakers and buy a dedicated sub amp.

I'd go 4ch first too if I were you. One that makes good power and has flexible Xover controls. That's what I did.... still using it on my highs.