Short version: which of the above would you buy to set up as a thump machine? My Kala U-Bass has renewed my interest in late 60s and 70s style P-bass funk (Meters, Funkadelic, Curtis Mayfield, Jamerson, Bootsy, etc) and darker sounds. I am using a very bright tone in one band, but could get much thumpier in the other one where I have been using the U-bass. I love the U-Bass but its G string just gets lost in our mix. So I'm thinking of either buying or putting together a 4-string thump machine, but the hitch is I really like jazz bass necks. Or at least I think I do. I also like lightweight basses (under 9# seems to be the thing, and good balance matters). My favourite necks ever in 4-string are my Modulus Bassstar (jazz profile, thinnish but not Geddy thin), Lull P4, and G&L #8 (beefier than the other two). I was surprised with liking the American Standard Precision neck, though, so I may not be as picky as I think (perhaps I read too much talkbass?). My options, as I see them: Replace fretless neck on my 79-80 Precision with a fretted neck (Fender? Warmoth?), but then I lose my fretless. Build my own via Warmoth's bodies in stock and a custom neck (or go short scale for extra thump) Used American standard Precision? But the bridge is high-mass. Used G&L LB-100 with #8 neck (or buy a new one in Empress or something)? The problem is the heavy bridge. Skip it all and just put some darker flats on my G&L L2000. Used Lakland Skyline 44-64 custom, except I'm not totally in love with their neck for some reason, though it could have just been that bass. Blow it out and get a Lull P4. What would you do?