I seem to have been so fortunate to meet such friendly vendors and members, who have taken the time to assist me with my questions.  Maybe Renderosity is just that kind of place.  Thank you so much for your reply.  The vendor I spoke with who created the products did in fact mention there may be a problem with shaders designed for Poser 5 and up, the Mat files he felt would still work were designed for Poser 4, out at the time he created the 3d models I was looking at.  I appreciate your comments praising Daz Studio programs as I am really set up for Daz, and all my products I have at this time are Daz Studio products.  I also cannot afford Poser right now.  I will focus on Daz Studio, at pick up the DS 3 advanced, it is on sale for a very good price at this time.  Thanks for the advice on Bryce and it's not being the most current program  to use.  I have just purchased a new guide to Daz Studio, still available at daz3d.com for $20, which comes with some great free 3d model content, but also has included the "full version" of Carrara Pro 6 and Hexagon 2.5.  Really fantastic offer from daz3d.com.  They have an upgrade from Carrara Pro 6 to Carrara Pro 7 for only $118(?).  The original Carrar Pro 7 costs over $300 by itself.  Something for members here to look into if interested in these programs.
Thank you again for your time and help, and advice about all of the various render programs.