I've seen the 04-05 model civics retro fitted on the low beams, but can the 01-03 headlights be fitted to have the projector lenses?

 

Plenty of retro-fits for examples here: http://www.civicforums.com/forums/

 

https://honda-tech.com/forums/honda-civic-2001-2005-78/official-em2-es1-es2-picture-thread-2183375/

https://honda-tech.com/forums/honda-civic-2001-2005-78/official-em2-es1-es2-build-links-2797207/

A number of people have retro-fitted their OEM headlights. (both 01-03, as well as 04-05)

 

Yes. Pretty much any car can have the headlights retro'd

 

If your looking for a simple retro-fit then look into morimoto mini projectors, they're available from theretrofitsource for around $120. Unlike most retro-fits that involve a lot of custom cutting and making your own aiming mechanism or eliminating it all together, the morimotos only require opening up the headlight and fitting them in. They also are an excellent performing projector, better than many oem projectors actually.

There's a diy for installing them available on the site lazlong linked to as well as a number of members who have installed them recently who can give you a review and advice.