You need to learn more about scales and chords than just simply that you can use an Ionian mode or scale over a major chord. This simply is not going to cut it for you to improve your lead bass playing ability. Dorian and Aeolian modes are used by Joe Satriani for example, but what does that really mean or do for you? There is a vast curriculum of lead bass theory that you won't find in a single book on lead ideas, you need a whole bass school at your fingertips that will give you the foundation you need to learn more than a surface level knowledge on how to match bass chords and scales.

Lead bass playing is an art that has very precise and logical bass methods of bass harmony and chord progression arrangement. Instead of making that next bass equipment or instrument purchase, you may want to get a serious bass education program on lead bass playing.