x2 on basic maintenance first. Make sure your lower intake gaskets are in good shape, change the fuel filter, new PVC, plugs and wires, change the supercharger oil and be proactive and replace the coupler.

After that my first mod would be an intake. I like the Wizair, to which I would add an Amsoil or AEM DryFlow filter, but you can choose whichever intake you like.

After that it's all about how fast you want to go and what your budget looks like.