Caps each have their own sound. You will need to identify what kind of a resulting sound you are looking for before you go down the replacement path.
If you're looking for open and airy and precise and clean and extended and textured, then teflons may be appropriate.
If you're looking for midrange warmth and texture and palpability, but are less concerned with top and bottom end extension or precision, then oil caps may be appropriate.
Yes, it's as much an art as a science, so talk to someone who has experience with different brands and types and can help you achieve your "optimal" sound.
Bob