New motor vs. rebuilt motor?

I have a 96 honda prelude vtec (engine is 2.2 liter, h22a model) the engine has 170k on it and it runs decently. The vtec kicks in good but I am hearing alot of engine noise, like tapping and just weird noises in general. I have had problems with its idle since I bought it and have tried lots of things to fix it. I just feel like if i want to keep this car for a while that it might be time for a new motor. I have pulled engines before (i used to have a 89 toyota supra turbo) and was wondering if It would be more cost effective and still be reliable for me to pull the engine myself and have it taken to a machine shop to have it rebuilt? I know there are many variables for the cost of this but is there a ballpark price? I ume that If i was to pull the engine that would be a good time to replace the clutch (which needs to be done anyway) but are there any other small to medium performance upgrades that would be good to get done while its out?