best value on a trigger with line release

Euro Gun or midle handle??

i too am interested in attempting to build one, more to understand the finepoints of the speargun. my question is also with the handle. i notice you can simply buy the handles and add a barrel and muzzel. if i would like the option to possibly add more bands then does it realy matter which handle/trigger setup you use. for example jbl has handles that i think are standard model from the 21" size gun up thru 48" are these all the same or were does the trigger mechanisms change is it at the 41"size. and do you need aspecial upgraded trigger to do a 48 with three bands. ive seen some posts of people who damaged thier triggers after adding or changing bands. also noticed that some people prefer omar triggers as they are smoother firing than the jbls. .... i think my goal would be to build a set up that i have multple shafts but use the a single muzzel and handle-trig. gun size would be 48" and 21" that would get me two different styles for different applications. both euros or euro mods. i like the pistol grip, but dont like the small butt at the end. need a wider surface for loading comfort.what seyeth the board members to my idea?