I wouldn't go with the stock supercharger since the only ones you can get nowadays are used and over 2k. They are also roots type, so no intercooling. They do a max of around 10psi with the right pulley, but also with a nice amount of heat.
The turbo is an option, but most setups (Camry) I have seen have you remove cruise control and relocate your battery. The tubing is a little messy since one set of the exhaust ports is near the firewall.
If you are serious about getting some power, you will also have to work on the transmission. I believe it handles something along the lines of 270 lbs of torque or less. So rebuild it and reinforce, or convert to a camry/es300 5-speed manual. Torque converter would be the first thing to look at if keeping it automatic.
For serious power, manual is your best option, since you will probably have to get an aftermarket engine management system (Motec or AEM). I have been looking at probably going this route, with a centrifugal supercharger for forced induction (ProCharge C-2). Takes less space than turbo, and gives you ability to intercool. For this you will have to reinforce the rods/pistons and what not, as the 1MZ-FE is known to be little weak, mainly the rods.
http://www.turbomagazine.com/tech/03...ect/index.html
This would be a good read for this. Although it's for an MR2, they are using the engine that's in our car, and go over everything that would be needed for serious power.
So there you go. I'm really thinking about this route, but most people laugh at it. Eventually, when they see it done, it'll be a different story.