I say wait. After 3 months of use the lumen's drop on all HID bulbs. Most replace them after a year so they sound like they need to be replaced. Sounds like the set-up was custom built so it might not be suitable to your needs. If you plant on making a concealed closet grow, then i would get a digital ballast. The hum from a standard one tends to get louder over time. Not only will you save money on electricity with an electronic one but the hum will be reduced greatly. I also thing a digital one runs cooler as well so less heat in the grow room. I would almost use your boxes that you made for veg and use your closet for flowering. finding a proper table for that might be a pain too. 800 ghp for a small one is a bit overkill. You can find deals all day long so if you pass one up don't worry. You can make a wonderful dwc unit that might be a little better for first time growers.
You need to plan on getting a ph meter as well. having a TDS meter can also help.
thats my .02 cents.

Cheers!