Azimoth

I would like to buy the new Imac, however the graphics cards are not listed on the web site. IM currently using a mac mini and works rather well however it is the 2011 model. I cant find the porper way to contac linden so if you have any imput please let me know. The configurations im looking at are asfollow in order of price low to high. would like the cheaper one but if i haveto i will spend the extra clams on the next one up 2.7GHz Quad-core Intel Core i5, Turbo Boost up to 3.2GHz8GB 1600MHz DDR3 SDRAM - 2x4GB1TB Serial ATA Drive @ 5400 rpmNVIDIA GeForce GT 640M 512MB GDDR5 or 3.1GHz Quad-core Intel Core i7, Turbo Boost up to 3.9GHz8GB 1600MHz DDR3 SDRAM - 2x4GB1TB Serial ATA Drive @ 5400 rpmNVIDIA GeForce GT 650M 512MB GDDR5 thankyou in advance