I've been gassing for a DB680 for a while now, so don't get one because they're damn near impossible to find and I want one. The SVPCL is the front-end of an SVT so I assume that would be your first choice. The Alembic F1-X is awesome if you can find one at a sweet price. The poor man's F1-X, the Trace Elliot V-type can usually be found for a good price and it has a monstrous tube tone. I had one for a little while, it's really versatile and nails the old school SVT tone. Another good one is the Fender TBP-1, I haven't had any experience with it but I've heard good things. Get an all-tube power amp too if you want to have some real fun. I cringe every time I have to move my Strategy 400, but it's totally worth it to have 12 big scary power tubes in your rack.