the stock power steering is pretty light but theres no reason it cant be accurate and precise.
there is some adjustment in the steering box and if the wear is excessive, you can replace it with a new one.
the rams also wear as do ball joints etc. I agree with Jamison. Check out whats good and bad with your current steering and suspension and then make some decisions.
You can alwaysreplace the whole lot with rack and pinion steering but it is more expensive and you will be disappointed if the rest of the suspension is worn.
check out
http://www.rrs-online.com.au/index.phpas an example of the types of "modernising" stuff available. they publish their prices but make sure you are sitting down
