Anyone who read that you chose that business plan will have the idea that you actually can make such a website and you just need help with the marketing and promotion part .
My suggestion will be to best outsource the business part and for marketing , well , there are undless flash gaming sites on the net , so you actually need to get have your exclusive ATTRACTIVE games , you can submit demo or 1-2 levels on the common website and the rest of the levels will be on your site , also very important here to catch your visitors email to notify them when you will have new games or do a survey with them on what games they prefer so you actually get their loyalty .
Cheers