I don't know too much about the G6 but what I CAN tell you is that for goldie filtration the general consensus is that you want a minimum of 10x the tank's volume in GPH for filtration. So you need a filter / combination of filters with a total rating of at least 1100 GPH.
As for stocking, the rule of thumb with fancies is 20g for the first fish and 10 for each additional fish. I suggest you take at least 10g off the total tank volume for substrate & decorations. I am gonna say that 9 goldies would be a nice, conservative number. Or you could do 8, the lucky number, which has good chi :) The MAXIMUM you will want in there is 11 but I would only consider this after the tank is stocked at 9. You don't want to be committing yourself to multiple water changes per week!
For plants I recommend (for obvious reasons) a low-light setup... I strongly recommend reading some of Byron's stickies because he is very practiced at the art of creating thriving low-light, low-tech planted tanks. Some plants that I have personally experienced great success with are:
species (very tough, nasty tasting leaves)
-Moss of any sort
-Heavy rooters like cryptocorynes, vals, swords, vals, etc. that are hard to uproot.
Did you say you have one 30" fixture? Not sure if that will suffice lengthwise. Dont' know how long your tank is but you will want something close to the length of the tank.