Re: Piezo system on a Universe?
Yes, the piezo sounds like an acoustic(more or less). You gotta keep in mind that with these contact pickups, you get a different tone from different spots on the guitar. The closer you mount it to the bridge, the brighter it gets. Mounting the pickup directly onto the sustain block resulted in a very bright sound. Reversing the pickup (ie. turning the pickup around to it stuck onto the guitar body and not the sustain block) resulted in warmer tone. Mind you, this is probably where the acoustic properties of a solid body really makes a difference. Where as mounting it directly to the sustain block wouldn't make that much of a difference.
That part from Allparts would be the similar kind. Since the majority of people around here seem to prefer Dimarzio pickups, I'd like to point out that Dimarzio also makes a pickup like this (DP130 -The Acoustic Model).
Although I did have my trem blocked, there's no reason why you couldn't still use the trem. The problem is, making sure you don't crush the pickup when you use the trem. I never actually measured the clearance available on the upper part of the trem(where the sustain block attaches to the trem itself), but if there's enough clearance between the trem and the body even after diving on the trem, I guess the pickup could go there. The spot I'm referring to is the area where I actually have my wood block(and a little above).
Alternatively you could try to mount the pickups elsewhere. Maybe somewhere else in the trem cavity or maybe in the control cavity. Keep in mind that the farther you go from the trem block, the less vibes it'll pick up.
In terms of a preamp, you could also try the EMG after burner that I tried once. It does work, since it'll give you a variable +20dB boost in signal, but that still wouldn't be a true volume for the piezo. I'll probably do this piezo thing on the J-Custom that's coming my way. Seeing that the guitar is destined for a new paint job/new body entirely, I'll just wire it up with a piezo to demonstrate how I did it before. (Just need a digital camera or bug someone to lend me thiers again..)
Hope that helps,