Printer that fits these requirements

I'm looking for a first 3D printer, and I'm not too sure which printer, and derivative is the most suitable.
I've selected a parametric delta style over Cartesian due to its greater precision and accuracy, as well as its cylindrical print base.
I've done some research, but there are a lot of RepRap PDMs, and even more derivatives from them, and I'm not entirely sure which I should get.
These are my preferences:
- Repeatability as high as possible, less than 50microns
- High resolution
- Best upgrades and mods (heated printbed, filament compatibility, multiple extruders, etc)
- Readily interchangeable and upgradeable components
- Assembly complexity isn't a concern
- Speed shouldn't be too unreasonably slow but less of a consideration
- Size not a concern as long as it is greater than 6" diameter
Best variants in your opinion??

Thanks

Where did you get that Deltas are more accurate than cartesian systems? They aren't. In fact they have varying resolution across the bed. I would recommend something like a CoreXY build or a well built Kossel with linear rails/Vslot and aluminum corner vertices.

Any printer type will meet your requirements. We need more details about your max build size and height, and what types of things you will be printing. That will drive what type of printer is best for you.