The download of the ISO of windows 10 v1803 from the microsoft page is only available if it is accessed from a device that does not have windows installed, example android, otherwise appear in options only the tools of update and media creation tool Microsoft and its Customer Service User ..
I tried to update version 1803 on my Acer Iconia W510 tablet with keyboard (which already have version 1709) and here's it says: Sighs.....
It's available for WIndows users when MSFT opens it, for now the techbench unlocked scripts or websites can offer the links.
My Hyper-V install went very well from b16299.402 to b17034.1 off a x64 DVD & DL .ISO by MS Media Creation Tool. The Hyper-V is installed on my MS Test partition w/ b17655.1 OS. The install took 25 minutes to hit the desktop. Lots of new lock screen/spotlight images... nice. Glad I tested it 1st on Hyper-V before installing this one on the Main Rig. Like to be a bit cautious on new W10 feature updates.
I have 17134.5 as well and wont be paving over it until a publicly available CU for RS4 is available.