Solid Hardwood, Engineered and Laminate Flooring - Where to but hardwood floor

I would like to purchase and install (myself) a 3/4" x 3" (or up to 3.5") unfinished red oak floor. I have someone to finish the floor already. I ned to find a place that has decent prices on high quality planks in clear or a select or better grade. I have tried some of the web vendors, but their prices are in the $4 range, and for $1 more I can buy the 50 year pre-finished. Also, while I am handy, I have never installed a wood floor. There is one there now but in bad condition and with many gaps. It is beveled and a dark finish and I want a light finishd. I also want to screw down the subfloor when I pull up the old floor to eliminate numerous squeeks. Finally, we just replaced the carpeted plywood stairs with red oak treads, so I want the floor to match the edging and treads. How much work is 500 square feet - what am I getting in to?