Does your car have air conditioning? If so, you'll want to pull the radiator out to replace the fan clutch and water pump. If you just want to do the hoses and flush, you're probably looking at a couple of hours.
I replaced my AC condesor, thermostat, fan clutch and water pump, stripped and painted my radiator, oil cooler, shroud, and fan, and put it back together over a weekend. Total of about 15 hours. I don't remember how much of that time was stripping and painting but it had to be over half. (Didn't count drying time overnight) I think I remember The water pump was $70 and the fan clutch $150.
Also, careful with the bolts in the thermostat housing. Mine were really stuck and I was very careful not to strip them. Good luck and do some back stretches before you start. It helped to have a second person when putting the radiator back in.
Ray
'68 280SL 4-spd Coupe