Yes...if you have subs without an amp, they will sound like shit. Since you're going with a 10" and a single channel amp you will be able to get a fairly good price for it, I personally love alpine, and all of my stereo components are made by them.
My ideal setup would be something like this:
A good amp is really important, it is what will make your sub sound so nice. As you can see, this sub is 400W RMS at 4 Ohms and 600W RMS at 2 Ohm. If you have a Dual Voice Coil 4 Ohm sub, like the one I linked, you can wire it down to 2 Ohm resistance, giving it 600W RMS.
You're not drunk if you can lie on the floor without holding on
(n.): Something that can be looked down on and approved of at the same time.