[TriLUG] tips for a new, RPI-based house server

[Pete Soper via TriLUG]

Dear Supremo System Designers and Maintainers,

Roughly seven years ago I slapped together a Samba server on an original 
Odroid C4 (think Raspberry Pi 2, but well before that came out) running 
Ubuntu 14.04. The rotating drives were set to spin down after relatively 
short idle times and I just lived with the few seconds pause while they 
spun up (i.e. this has zero pain factor). It has silently done it's job 
while emulating a night light wrt power dissipation, but it's time to 
swap in something better before my luck runs out. I want to swap vs 
upgrade to avoid any down time or time spent with no service 'cause I 
hosed something in the middle and can't figure out how to recover.

I have a 4GB RPI 4 with heat sinks and fan, a USB 3 powered hub and pair 
of 2TB USB 3 interfaced drives for a RAID 1. I may or may not use the 
old trick to have the RPI's root filesystem on another USB drive vs 
using an SD card (i.e. the SD card would be for boot loading only).

The questions are what OS to use, whether Samba is still the right 
choice, and , as I may want the thing to provide local DNS caching, spam 
sink, etc, what the best combo of software infrastructure for that might 
be? My wife has to be able to access some of the storage with zero 
hassle using Windows (7 and 10) but she could live with a bit lower 
performance than what I might get with another Linux system as her 
accesses are few and far between (and she's used to Windows being dog 
slow anyway!) The RPI will have wired ethernet connection to the house 
router and I have no current plans or desires to touch the RPI 4's wifi 
or bluetooth, let alone it's GPIO et all: that's well over the horizon 
and not on the table here.

Left to my own devices I'd go with Debian 10 + Samba and either bind 9 
or a more recent equivalent but without much clue about advantages of 
one or the other. This won't be a general purpose system, so, for 
example, the fact that app X won't run on Debian but does on Ubuntu is 
not relevant. All my experience for maybe 15 years has been with Debian 
or derivatives, so I'm not keen about Fedora, Arch, Gentoo, etc. The 
spam sink is appealing but up to now I've never tried one: I just use 
Adblock with my browser. But I'm both ignorant and conflicted about the 
latter, as, for example, when I visit the amateur radio classifieds at 
qth.com I don't want to disable those ads and can "pause" the blocker 
for the specific site, as those ads are the means of support and the guy 
that runs it is a personal friend. I guess I can just "white list" sites 
like these? (No idea what I'm talking about with this last question).

So, what do you recommend?

-Pete