urgent advice needed for 100% Ubuntu-compatible desktop

[M. Fioretti]

Greetings,

I badly need to buy or assemble a desktop with the
features below, as soon as possible. The help I badly
need is names of hardware components fitting the specs
below. All the rest (installation, post install config...)
I can do myself, likey, but I know next to nothing when
it comes to what hardware/brands are good or bad these
days.

The requirements:

100% Ubuntu compatible (I'm going to install 16.04LTS on it)
SILENT
the lower the power consumption, the better
reliable
components quickly orderable online
optimized for these kinds of work:

heavy "office work"= fast and responsive, even with 20+ tabs
of Firefox open, and 5/6 big libreoffice docs, slideshows..
digikam and maybe gimp... all open at the same time
(I know this also depends on the window manager, desktop environment
etc.. but I'll deal with that later)

heavy text processing = parsing BIG text files with perl, python,
awk... (I know this is not a problem, just saying for completeness)

simple video editing: a toy project I can't delay anymore is
digitize family VHS tapes: grab from several tapes the only few
minutes that are really worth saving, re-assemble them in one
sequence, put them on DVD

that's it. I need NO 3D effects, or high quality sound output,
just a mic+speaker for skype calls. And I surely will not need
this computer for gaming

Side question: since I have to buy hardware, I'd also like a good,
full size, silent keyboard WITH cable (no wireless) but WITHOUT numeric 
keypad.
Suggestions?


Thanks a thousands to all who will help. As I said, I know what
I need and how to install/configure Linux, but really need hand-holding
when it's time to choose hardware

Marco
-- 
http://mfioretti.com