DELL , imo is the best value for your money. The biggest wide screen LCD monitor, lots of RAM as mentioned by others, and you are off to the races.
Because we use the mouse so much, you may want to look at different types of mouse (at Staples, is a good place, or Future Shop) to find something easy on your wrist over the verry very long term. The wrist is a niggling , long term hard to fix problem when it starts, so why not address it now.