I can tell you now that a supercharger won't be available for under 3 grand. At least, I've never found one. However, turbo charging might work well for that motor. It's all about how you set it up and what kind of things the motor needs to do.
I'm gonna build one of these for a ranger hoping to get an 11 sec car while keeping it a daily, so ill be doing big turbo and big cams. That will put my power band at a better for racing 5000rpm band.
But If you are towing you won't necessarily need cams or a big turbo, just a slight timing tune and some decent twins should give you a good low end build. It's all about what you are wanting out of it.
Custom building a turbo setup will be your cheapest route.
Find an oem turbo, and buy quality wastegate and bov, you should be fine.
3k is a good budget. I could build you one for that cost if you were closer to Philidelphia PA.