rekib posted a conversion of all 30 jerseys for NBA Live 06. It should work alright with NBA Live 2005, though you might have to resize the numbers. Check his thread in the NBA Live 06 section for the download link.
Open the number file with FshX, extract the numbers as .dds files, resize them accordingly with a program like GIMP or Photoshop (see some default number files for sizes), save and import the numbers back into the number file using FshX.
You'll need to extract the number file from the .vivs using the EA Graphics Editor. You can then either place the updated number file in the sgsm folder or import it back into the .viv using EAGE.