Normally I would say selling everything and starting again can be quite an expense….but with the advent of single dosing grinders like the Oro, Solo and Niche and their ease of use can make it a sensible decision. I can speak directly for the Niche, that the coffee saved vs a Mazzer Mini which I used to have (due to purging and dialling in hassles, pays for the Niche and I would imagine the same for an Oro in 5-7 years. In a sense, it’s a no-brainer. The workflow of a grinder like the Niche is really really good, the Oro is probably fine, but not quite as good as a Niche. Either grinder I think will make you happy and it might come down to a choice of flak vs Conical, which do you prefer the taste of…I’m sure others will chip in with advice.
I rarely make milk drinks, but it’s nice to have the facility and apart from the ECM Puristika, which has no steam boiler at all, the market is a bit limited on PID single boilers with good temperature control, so your into the dual boiler market there, something like the Elizabeth is ideal as are any dual boiler machines where you can switch the steam boiler off (which nowadays is most of them).
The HX which would give you better temperatures, but considering your existing kit I think it’s time for dual boiler world.
Something like the Lelit Bianca and a £500 single doser would give you a superb setup and for most people…endgame. If you ever upgraded from that6, it would be because you wanted to, not because you needed to.
Lelit Elizabeth and 500 single doser would be great for you and certainly not bust the budget
I’m sure others will come up with suggestions as well.
P.S. Thought you said a Mazzer Mini, I saw the next post from @LMSC that mentions a major and what @Cuprajake has done, so that’s well worth considering.