Depends on your skill level. I'd do it myself.... It pretty stright forward. 1 thing is making sure the hoses are on the correct side.. You do this by making the hoses with Green STB & Red PORT with Green & Red electrical tape BEFORE you pull them thru the chase. You will know if you hooked the up backwards..... When you turn Right..... Boat will Steer Left and Visa-Versa.
As to a Kit. Forget SeaStar.... Go to Uflex.... They are heavier duty and don't leak 3 to 5yrs down the road.