What shower with serviceable parts?

Let the rant commence, had a mira realm, running cold and cartridge was knackered a new cartridge was £141 pounds...... the shower cost me £220 so I bought a new shower. Split the old one to see if I could repair the cartridge let's just say it was a very "sealed" unit. 

Hansgrohe. New cartridge from NSS was £55. Needed a socket for a few quid from Halfords. As opposed to Hansgrohe’s own which was as much again. Mind you the showers are now a bit pricey. 

Not quite what you’re looking for but for what it’s worth I’ve got 3 Mira digital ceiling fed showers in the house, 2 of which are 10 years old. Living in a hard water area the idea of all the gubbins of the showers being in the loft with nothing buried behind tiles was very appealing as I could replace the units in minutes when they fail. 
in 10 years they’ve never failed. 
Very expensive tho 

Mira and Grohe but my recommendation would be a bar mixer from one of them that way you can just replace the whole valve simply. 

Another vote for Hansgrohe, had a couple of bits fail after ~15 years, one was 120Sek (12 quid) from the local DIY place. Only thing that had changed is one of the plated parts in the guts is now a dull grey instead of bright gold (think it was something to do with deletion of chromium plating) everything else was plug and play. Still a current model though.

The other part, a shaft in the tap body that wore out (thanks kids) required a new cartridge, which was 400sek/40 quid, the tap was discontinued 10 years ago. But the cartridge is now used in half a dozen similar looking taps.

Thanks all, some useful ideas here. 👍 

No idea about serviceability but we have 2 x Grohe showers that are both 20 years old and we've never had an issue.
(Thankfully!)