Re: why so long?
The longer tiller gets the helmsman's weight out of the stern more amidships, and provides maximum mechanical advantage. The only downside of a shorter tiller would/could be the effort to control it when the boat loads up the helm. Not sure if the C27 has a properly balanced rudder - if it does then a shorter stick won't be any trouble at all.
Really don't think going to a wheel is the answer here.. the boat's a bit small for that and your limited budget would be far better used for just about anything else. Also, on a boat of that size it puts the weight of the helmsman AND the steering system well aft where it does most harm.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)