Intel usually has some stocks of boards for warranty replacement etc for 'some time' after a board goes EOL (but not for sale anymore - although some retailers may still have 'old stock' for sale).
As to which you should choose, It depends what you're wanting - whether its the absolute cheapest price possible (which you may get with a product nearing EOL status) or whether you want the latest and (usually) greatest - often with a price to match.... Just because a board is approaching EOL it will still have the full warranty if bought through official channels but if for some reason it needs to be returned for repair or replacement under warranty, if they've run out of stock for the EOL product, you may receive a different (but similarly capable) board as a replacement. More 'mature' products are also more likely to have had any issues ironed out of them than 'bleeding edge' gear but that said once EOL status is achieved, Intel usually won't provide updated drivers and BIOS files etc.
Hie good people sorry to ask, on the same board (DH55HC) can I use an internal 2x2 tb hard drive or will I have problem?, I am using windows 7 64bit, 8gb ram, 1tb?
I recommend you creating a new thread for your issue. You can do it at this link:
The End of Live means that Intel ® will not sale more of this product. However, Intel ® Authorized Distributors or Retailers, as Flying_Kiwi says, may have this product in stock and they sell these items.
Intel does keep stocks of boards for warranty replacement in case that is needed.
My Best recommendation since this is a product marked as EOL is that if you can afford a new system, check for the newest Intel® products and update your system with a newer computer.