Nooch,
If you're gonna do it, do it right. I would ditch the spacers (sell 'em on ebay) and get the 4" suspension kit. You will clear 33's and it is not REQUIRED to get the SYE and it is not REQUIRED to regear. However, understand that you will loose power as a result of not regearing. I assume we're talking TJ since you have "spacers." Without the SYE, you will have to do a Transfer Case Drop kit. The only adverse affect to this is less ground clearance and less break over angle (BOA). If you like running 70 on the highway, you will want to regear. Since you have the 2.5 (like me) you almost assuredly have a manual transmission. You will not be able to use your 5th gear. Sure, you can shift into 5th, but there will be no power there (unless you're going downhill).
You can do power upgrades to help with the power loss (like me). Get a K&N air filter and a high-flow muffler (cat-back system). This will help a little. But don't expect miracles.
Oh yeah, we want before and after pics.
Corey