I use a Palmer PDI-09 its a passive box and very quiet, I only use it for getting my amp to the board but can be used the way you are asking!
This is a direct box with no speaker sim... don't think this will help the matter.
I know you said you wanted to avoid amps but a tube amp is really the other half of your instrument. An electric guitar may use a cable that looks like a keyboard patch cable, but it sends a completely different type of signal. I would heavily consider buying an inexpensive small tube amp before dumping coin into DI. I always play small gigs and I love my Blues Jr.
considering that I sadly have played so many places with such lousy soundmen that either won't mic the amp, make me play the house amp or even worse, just hand me a DI to plug my pedalboard and use my amp as monitor.
I make my living as a soundman, and that's three of the worst cardinal sins right there! who are these idiots and who's paying them to be soundmen?
The problem with the Palmer is you have to bring your amp to the gig, and then a rack to hold the palmer.
Although he did not specify, my guess is the original poster is looking for an easier way out, meaning not have to bring your entire rig to a gig, maybe for lack of space on stage, or the pay being to low, etc, etc.
So just the pedal board, and a guitar, and straight to the board...