Its all over the board, but from what I can tell, if you want to get a USB device ( block Erupter USB ~300 gh/s ) you can pretty much find one and get it within the week.
Too bad that the current price and BTC difficulty of these , they will not generate enough BTC to pay for themselves. It is mostly a novelty item. For anything more substantial with quick delivery you will have to buy used from a marketplace or auction site.
If you are looking at new ASIC rigs, it appears that late August -September for a lot of the Klondike boards - Avalon clones. If you browse the custom Hardware forum, you can get a rough idea from the posts in there.
https://bitcointalk.org/index.php?topic=209750.0Cheers,
Pixl8tr