Companies XML Data Feed imported to magento

I need a solution for a companies XML Data feed importing to my Magento store. I need to be able to fix perimeters before hand (send products to my correct category,set prices, etc.) I need to be able to re update/ or auto update at least several time a day, every day so that it updates out of stock items, new products, etc Also, they have products that are the same, except say the color, that they have listed as separate products. This causes a problem in my mind, because it make take 5 pages to show one shirt. One page for blue shirt, one for red shirt,etc. Also the same prob. goes for diff sizes, or the same product. There needs to be a color swatch, and size drop down on these kind of product situations. But also the Feed would need fixed somehow to only come in as one product I believe. I am not sure what a solution is to this. I am not sure if my developer is ready for this to be done, but I am trying to be ahead of it. There is a lot of products. I am guessing over 5,000. Please leave me a cost, your solution to the problem, and a number to reach you with a time to discuss. I also have a company with I believe a CSV File that I will be adding later. Thank you, Lisa