Alright I got 3 questions.
1. Is the jeep straight six with a performance header and maybe a performance intake manifold and maybe maybe a performance cam shaft  a sufficient building block for a wrangler with some big tires and a little bit of a lift? People with straight six give me some feelings and thoughts on it.
2. What are some somewhat inexpensive upgrades for the engine that help performance and power?(I was thinking somewhere on the lines of cold air intake etc.
3. Where are some good places in colorado to get jeeps with blown engines for cheap?  

Air intake maybe 5hp.

A chip which re-tunes the motor to run on premium and has negative effects on mpg and harms the catalytic converter and o2 sensors over time, 10hp.

Cat back, cool sound and no hp.

Horsepower isn't cheap. Three ways to get meaningful hp from the 4.0L. Turbo Charge, Super Charge or Stroker.

Intake, chips/programmers and cat backs are the most expensive for what they provide, combined, less than 15hp for $1000.  

horsepower is no substitute for proper gearing.

proper gearing.... $1200,(if someone else does the work).

improved ecconomy and peromance gains.