Toyota pickup audio speakers

Guys, I need advice- I need to change the speakers in my 91' Toyota pickup. I don't want to spend too much, yet I don't want to install junk. I don't need the speakers to thump the chest of the guy next to me at a stop light. Mostly I'm a talk radio geek who occasionally likes to listen to some Country music tunes. The deck is a Pioneer DEH-43 35W-4 (whatever that means). Do I need to have a amplifier for this tiny little truck? Also how do I filter out the static sound on the radio when driving along side high voltage electric wires? I know these are dumb questions, but please be patient.

The only dumb question is the question that is not asked.
Go to Circuit City, Best Buy, Goodguys and see what they have. These type of stores usually put the speakers on display so you can listen to them. Shouldn't need an amp. I got a nice pair of Kenwood's for my roadster from Best Buy for less than $40- and I think they sound good. Definitely better than the cheap pair I got at Target for my pick-up.