Should you be carefully about preordering anything ?!
I lost money with Avalon preoder, I lost money with Bitmine preorder, not going to lose anything more - no more preorders.
You can buy cloud power quite soon real time.

And difficulty is going up:
http://www.coindesk.com/megabigpower-launches-global-franchisee-network-add-50phs-per-month-bitcoin-network/