Combined design...
Hi Guys
Tom mentioned the Space Island group, who have a modified STS with liquid-fuelled boosters.
http://www.spaceislandgroup.com/Gallery/Launch/index.html
Meanwhile Buzz Aldrin's company has the Starbooster design for liquid-fuelled fly-back boosters...
http://www.starbooster.com/
I'd suggest that the two designs can be combined synergistically and would provide a cheaper ride to space for the Island people and a steady market for Buzz's company.
Adam