Don't fart about with acoustic bass guitars, guitarrons or any other crap. Get a stand-up bass (double bass). Why? Because they are L-O-U-D, sound wonderful, encourage muscle-growth in the hands and wrists and, most importantly, a stand-up-bass-player just looks so-o-o-o-o cool. :-) :-)

If the absence of frets bothers you, just do what the S-u-B player in my R&R band did, and paint some marks on the side of the neck at the appropriate points. Easy-Peasy.