Tone starts at the fingers then goes from the strings to the pickups, down the cable, into effects, then the amp and finally out the speaker. there are so many factors that can easily destroy the tone you are looking for.
First, you need to have a solid playing foundation. then think about your guitar and how well it plays. Next take a look at your amp. a 10 watt solid state practice amp will probably not sound as good as a custom marshall stack. finally, what effects are you going to run. chorus, flanger, reverb? this is a whole can of worms that is well beyond my knowledge base.
Now back to the squire. I have heard some people love them while others hate them. Personally, I think they are really cool guitars. If it is setup properly and you really enjoy how it plays, then go for a pickup swap. just keep in mind that so many things affect tone and that $100 bucks for pickups could have been better spent elswhere.
