I agree with jolly that bass lines are more restrictive,for obvious reasons.It sounds like variety in technique is what you're after,as opposed to variations in key or melody.Using the Cmaj7 shape posted earlier,it is possible to do the old ascend,tap on the 7th,slide up to the root,and descend trick,among a million other variations.The tap-slide glissando technique is not exactly a new one,but as effective for bass as guitar.Scale and triad sequencing and pedal point are also useful techniques.In closing,it sounds like you're a guitar shredder in a bass players disguise.This leads me to believe that a 5 or 6 string bass or a return to guitar may be an eventuality for you.As was said before,I think the shredding bassist is best left for individual soloing,not in a song context.