Manny,
The next issue of OGR has a Collector's Gallery article about both the MPC Blue Comet and C A engines which you will find valuable for background in making your decision. I can echo most of the posters who say the engines are rugged , attractive and generally reliable.
I use more modern Lionel sound cars in place of the original Sound of Steam and C A whistle. Details are in the Collector's Gallery article, which I recommend for anyone interested in these locomotives.
Ed Boyle