need advice on what to purchase

My Toshiba satellite C655 with win 7 has a bad fan so it is over heating I Purchased a Toshiba satellite S855D- s5120 to replace it but I can not get used to win 8 to save my hide . I work on line and need to have the ability to have many browsers open at the same time and many tabs on each

I want to get a good machine while win 7 machines still can be had but I am so over whelmed by the choices

I am trying to stay under 1000.00
so far I know
I want windows 7 ( have not had any luck getting used to windows 8 I love using windows photo gallery and it does not seem to work well with windows 8 )
I want a min of 3.4 GHZ
and 8 or more of ram
and at least a TB of HD
and I want to change back to a desk top so if a fan goes bad I can pull it and replace

but I am going back and forth between dell , asus and cyberpower
need some real help figuring out what is most essential for my type of use ( RAM , Processor ,? )
I manage several ebay shops and 2 web sites so time is spent editing photos , writing listings and being able to pop in and out of all the different pages I manage with out having to open and close things

what is the most important to handle having so many things going on ? please give me some ideas