Thanks for your suggestion! Just been playing with some different sans-serif and serif fonts to have a look ... not sure I like all Serif - may end up with a mix - Arial in the header and titles and a serif font in the body? Will test with some people :-)

Research: serif font (Cambria, Times, TNR, etc) in the body, 8-12 words per line is generally considered most readable. Check out how Medium does it.