Rega P6 cartridge upgrade

Several recent discussions mention that spacers are often needed to raise the arm a few mm, as many Rega cartridges are only 14 mm high, many/most are taller, 17mm perhaps, some as tall as 21 mm, and Rega based arms are not height adjustable.

https://forum.audiogon.com/discussions/cartridge-setup-question-for-rega-p10-with-hana-blue

this split design lets you slip them in without disconnecting the arm’s ground wire, cable  ... and has options for a variety of heights

https://www.acoustic-signature.com/products/accessories/rega-spacer-set/

Ortofon has a low profile cartridge body specifically for Rega arms

"The new 2MR

Ortofon 2MR features a specially designed cartridge housing tailored for turntables and tonearms like Rega matching their requirement for low-form factor cartridges"

4 versions, However, they all have aluminum cantilevers,

I would rather have a Microline or Line Contact on Boron, and use the spacers

here’s Audio Technica’s MM for $330.

https://www.audio-technica.com/en-us/at-vm745xml

their MC with boron is $900.

https://www.audio-technica.com/en-us/cartridges/type/moving-coil/at33xmlb

This place is a REGA dealer located in your neck of the woods. 

Fidelis Audio - Premium High-End Audio Equipment

also needing a spacer, I highly recommend risking a used AT160ML, you get it’s gold plated beryllium tube cantilever and Microline stylus. It tracks at 1.25 gm

https://www.ebay.com/itm/376955688926?mkrid=711-53200-19255-0&campid=5338381866&toolid=10001&customid=7168b744-0753-11f1-8921-303030653534

I got lucky, I risked used: my Sumiko Talisman S; both of my AT160ML’s; and an AT150e body with an AT160ML stylus all play and sound great.

Future: if cantilever good, have VAS put a new Line Contact tip in it.

If I break the cantilever: any current production VMN stylus will fit these vintage bodies, 3 options have boron cantilevers

AT-VMN45xML (microlinear/nude/boron cantilever)
AT-VMN50xSH (Shibata/nude/boron cantilever)
AT-VMN60xSL (special line contact/nude/boron cantilever)

https://www.audio-technica.com/en-eu/support/which-stylus-can-i-use-to-replace-my-discontinued-model

I am happy with my nd5, you could try the Nd7?

 but I now live 6 hours away from NJ

you also live 6 hours from the UK :)

What is your goal for changing the cartridge and what phono stage are you using?