choosing between imacs and other options need help

[PS590]

i currently have the 24 inch imac and a secondary 21 inch screen.

i am selling just the imac to someone who needs it for about 1500

i will need to buy a replacement, but am unsure of what to do

should i buy a new 21.5 inch and save some money
buy a new 27 inch with some extra money
buy a old referb 24 and save some money
buy an old refurb 20 inch, and a referb aluminum 13 macobok for only about 200 extra

thanks a lot just tell me which option you think i should do or suggest another one

 

[Hellhammer]

Do you need a laptop? 27" iMac would look ridiculous with 21" secondary screen and I think you would be fine with dual 21"s. Tell us more about your computing habits so we can help you to get the right model