Unbiased presets like "19. Metropolis Light Transport" are always safe, they take longer to render, but if you are not familiar with biased settings, you probably will save time. You might want to look on http://www.kerkythea.net/phpBB2/viewtopic.php?t=9803 for some biased optimization, but generally better start from basics with getting started tutorial http://www.kerkythea.net/joomla/index.php?option=com_remository&Itemid=42&func=fileinfo&id=89 and Fast Start 4Architects http://www.kerkythea.net/phpBB2/viewtopic.php?p=63986#63986
Also read trough the tutorials master list http://www.kerkythea.net/forum/viewtopic.php?f=16&t=5720
There is not much benefit from caustics in model like this (if you looking biased speed). Also you appear to have some modeling issues with light components, make sure that they don't intersect with geometry (as that gives moire pattern on surfaces).
