The ballast that is shown in that kit is only capable of running HPS bulbs. A 400w would be obviously better but judging by the inline duct fan that comes with the kit you probably won't be able to vent enough heat out. The specs rate the fan at 250cfm but thats usually when used as an intake booster. If odor is a problem then you will want to look at getting a can type fan along this line
http://www.htgsupply.com/Product-GrowBright-%206in-High-Velocity-Inline-Fan.asp as that other fan will get choked off by a carbon filter. I am running a 4 inch fan and wish I would have went with a 6 inch. Ventilation is one of the most important aspects of indoor growing but is often the most overlooked until the temps in your tent skyrocket over 90f.
Look for a switchable ballast if you are wanting to run MH during veg. While those kits are nice they usually consist of low end equipment and the money you save up front is often spent in turn buying replacements. I would search amazon for a tent similar to that and then look to buy a high quality ballast and vent system.