iMac 27" far and away.
imac 27 inch, macbook pro, and macbook air.
It is not possible to convert a DVD into an iMac.
21.5" or 27" Aluminum.
Apple no longer sells a 20" iMac. They sell a 21.5" and 27" iMac. Both come in aluminum.
As of this writing, the 3.5 GHz 27-inch iMac (with a 5K display) retails for $2,499 USD.
There is no 24" iMac for sale new. Your choices are 21.5" or 27".
The 27 inch iMac is 20.4 inches (51.7 cm) tall and the 21.5 inch iMac is 17.75 inches (45.1 cm) tall.
I do not have a 24" iMac. I have a 20" iMac. Apple no longer sells the 24" iMac. If you will click the Apple logo on the top left of your screen and then click About This Mac then More Info you can find the answer.
21 pounds
Yes, with no problem.
The technical specifications of the new iMac depend on which one you buy. There are 21.5" and 27" version which have processors ranging from 2.7GHz to 3.2GHz.
The 27" is $1,699 plus the state tax where you live. It has free shipping.