Thanks for all the replies.  I wrote up a list of all the choices I have based on your recommendations.  Bachmann makes some really nice pieces but, no, I wouldn't limit myself to strictly what that company makes.  However, I do like the large variety of EZ Track that is available and thus was going to stick with that brand.  This is a terrific forum.  Many thanks, again, to all of you.
Peter

Because of space factors, I need to work with a "dogbone" layout pattern using the EZ Track 15" Curves.  Can anyone recommend which Bachmann Engines (steam or diesel) as well as cars work well with such a tight radii?  Thanks!