600W Dual Spectrum HPS Sodium Bulb ??

hi guys i'am wanting to grow 9 plants in a 6ft x 6ft room and i was looking at buying one of these 600W Dual Spectrum HPS Sodium bulbs to grow... my question is i,ve been told these are new giving extra blue spectrum do you thing this will be enough to grow 9 large plants or should i go for a 1000w HPS ?

have a look let me know what you think please

http://cgi.ebay.co.uk/Sunmaster-600...arden_PlantsSeedsBulbs_JN?hash=item23042e897c