2000 Toyota Camry Solara Engine: 4cyl.

2000 Toyota Camry Solara
Engine: 4cyl, 2.2L, 5SFE
Mileage: 193,500
I have a 2000 Solara that is in fabulous overall shape. However, about 5 years ago it started using oil very rapidly. No leaks, no oil in the water, a light plume of smoke when starting in the morning, but within a week of driving the oil light would come on. Alarmed, I took it to a mechanic and they said to just start using high mileage oil. I did and that cut the consumption dramatically, but I still have to monitor oil usage closely. Over several weeks of driving the oil level slowly goes down and I have to keep topping it off. And, I still get a light plume of smoke when starting in the morning. I would like to fix this and return the engine to normal operating conditions.
My question:
I notice that there are many companies that sell rebuilt cylinder heads or have new heads for this engine. I have asked a three local mechanic shops about replacing the head with one of these new or rebuilt ones. All of them were cool to the idea saying that a new cylinder head would be too strong and could ruin the rest of the engine components. Is this really fact? A new head can kill an older engine? What are the chances? How do machine shops sell rebuilt heads if they are going to ruin the engines they are attached to? I would really like to fix up this problem. The rest of the car is just perfect.
Thanks!
Winston Foley
Cross Junction, VA