An izzo pompei spring lever is amazingly simple inside with few parts. Easy to remove the top plate and vast internal space to work in.

I used a Izzo Duetto for ~10years with minimal issues whatsoever fwiw.

Only changed because I got bit with the "try something new" bug. My brother is still using the Duetto without issue.

Fortunately we now have plenty of "tear down" videos on Youtube, kudos to WLL and other for doing that.
I'm not even a "technical" person when it comes to boilers and pipe and valve, but I can spot a well laid out machine from a so-so and a bad one. a well laid out internal means easier to access and diagnose and fix things when something eventually goes wrong. for that, my thumb up goes to ECM. Their build quality is not overrated.
And with that, stick with most popular machines, you will get more help and get parts easily.

I am in kind of in the same boat...
I have my Rocket R58 sense 2012, i love i, mostly used for espresso. I can't plumbed the machine and is was tricky all these years filling up reservoir. Not so many problem, change some parts which is of course resemble to after 11 years of using.
Now I would like to upgrade my Rocket and looking for La Marzocco Linea Micra...

I used my izzo pompei for a decade or more without any issues. Without a pump, there are few parts inside that would break down and it's incredibly robust as t's built to make many hundreds of shots daily.

The other day, I almost sprung for a Lelit Bianca V3 open box offered for sale at Seattle Coffee Gear, but when I was informed that the full warranty on the machine is only 1-year, that was unexpected.

In contrast new ECM/ Profitec machines carry a 3-year warranty. Even the used ECM/ Profitec units from Clive carry a 6-month warranty. For whatever reason, the 1-year warranty on new Lelit machines just doesn't inspire much confidence.

Could someone comment to the relative lengths of the respective warranties offered, and whether any of the ones mentioned would give one pause?

Also, could someone shed lights on where I could find local repair shops throughout the country? It seems that service is linked to the dealer from which a machine was bought, and with most of the higher-volume dealers on the coasts, it's a lot of faff if I ever need to ship a machine back.

I've had a Expobar Office lever since 2003. It has over 160,000 hours of service, average of 30 shots per week on it and I love the ability to repair it. It has been hard plumbed with RO water after 2 weeks of service.
I keep parts in stock for that reason. I have replaced one element, 3 OPV's, 8 pressure switches, 1 power switch, The OPV to boiler fittings and feed line (increased to 6mm) 1 Temp Limit, 3 vacuum valves, one controller, Rebuilt the group-head 4 times, and dozens of portafilter gaskets. Presently use silicone ones. I also have had to replace numerous electrical connectors and the boiler insulation.

That said, I used to work in the food repair industry. Including coffee machines. But today we are starting to try lighter roasts, so I find it difficult to be able to tune the machine for multiple coffees. So my son and wife teemed up and ordered me a new double boiler PID machine. Unfortunately they ordered it before talking to me and bought a La Mozocca Linea Micra. I was looking to buy the Profitec 700. A lot of the parts I have in stock would cross. But this is going to be a learning experience for sure. I love the repairability of a E-61 machine. But the stabile brew tenp controllability of the Linea Micra should be a great plus for shot quality. I think that is what they were going for.

An older commercial machine could fit your price point.
I was in the same situation as you in that I wanted a reliable machine, but my budget was much lower)

I bought an approximately 40 year old La Cimbali M20 Junior for Can$750
I bought it from a private seller that had used it as a personal machine. Prior to that it was used in a bakery/coffee shop.
It was poorly maintained and dirty, but still worked, no leaks, and it brewed a good coffee in spite of that.

Very simple design, easily servicable (only 2 screws to remove both side panels and lots of room to work.
Many of the parts may have changed, but in my case the newer model parts were all compatible for direct replacement without modification.
No automatic boiler fill (I added this myself. Very easy)
No dosimetric controls ( on/off brew switch)
Simple comercial (Sirai) pressurestat.

Built to not break down.

'Most' modern appliances are built with design "features" that add complexity with compromises on quality of parts to keep prices down.

In the case of my machine the age is a testament to a different design philosophy that puts durability and reliability higher in priority.

Machines like this are also available rebuilt and ready to use. I recently saw a Craigslist posting for a M21 Junior (circa 1990 model) for Can$1000

La Cimbali machines are damned near indestructible and are very capable HX machines that brew a great classic espresso shot.

If durability is your priority then this would be my recommendation.
I also have an affection for the esthetics of older machines
This seems to be reflected in the popularity of the 1961 Faema group. Faema licences their group to other manufacturers where La Cimbali did not, but they share the same vintage of design.