Turbo would not be a good choice for low end torque. They take time to spool up. I would do a procharger. Would not be too hard to make fit our application, just the most expensive part would be pistons and rods (est. $1000). So here would be a list of parts needed to procharge a liberty.
Procharger -
custom pistons - $400-800
custom rods - $400-800
Custom Brackets - $25-100
Custom Intake & Intercooler Plumbing - $25-500
Spare Pulley
B&G Chrysler Reflashed PCM - $450
Intercooler - Included w/ procharger
Obviously you'd need the procharger unit itself. The custom rods are need to handle the boost and additional power, you might aswell upgrade these since they will be removed to install the upgraded pistons. Pistons are needed to handle boost, our stock pistons have the rings sit to high and causes the boost to slip past them and fries your rings. I would suggest have pistons made w/ a lower compression to help with detanation. Brackets will be needed to bolt the procharger on to the engine. If you have basic machining skills you can fab up your own. Same thing w/ the intercooler and intake plumbing. If you have half a brain and a pipe bender you can do this yourself. The reflashed ecu will adjust your a/f ratio to run smoothly on boost. The intercool should come w/ your procharger kit. What this does is take the air that gets compressed and also heated from the friction inside the procharger and cools it down. This will need custom brackets to support it, pretty easy to make. The spare pulled would need to be welded to the stock crank pulley to a belt that turns the procharger.
Sorry it's late i'm bored, will reread in the morning and fix any errors or typos. I'm sure there are a lot.