Cartridge recommendation for a Rega Planar 3 with a RB330 tonearm with Rega dust cover?

I suggest you go beyond elliptical stylus shape on aluminum cantilever cartridges.

At least get an advanced profile, shibata, or one of the many different named line contact variations.

next, what cantilever design and material? rod, tube, tapered, boron, or

take a risk on vintage to get no longer made beryllium, and the combined advantage of lighter tracking force of only 1.25g

I just won another auction for an AT160ML for $130. with all the fees and shipping it will be less than $200. AT155 and AT150 are out there as well.

When it is worn, I can have the beryllium carefully retipped by VAS, or buy one of 3 new VMN stylus with boron cantilever that fit that AT160 body.

here’s one in Finland, seller says headshell not included). It has both overhang and azimuth adjustment, I would try to buy it. The ones from Yahoo Japan often include the headshell, 

https://www.finn.no/recommerce/forsale/item/435421429

They are advanced MM designs, I have a few MC cartridges, they are good, but I prefer the AT150ML and AT160ML MMs

.ps, I encourage you to think long, about getting a TT with a tonearm with adjustability and removable headshell, so you can have a true Mono cartridge, and a small collection of MM and MC cartridges, better yet two arms, Stereo and Mono on call instantly.

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top of your budget, $460. this is Ortofon's Line Contact, low profile for REGA's

https://www.audioadvisor.com/or2mrbronze?sku=NEW-OR2MRBRONZE

I just noticed, that Ortofon I linked tracks at only 1.5g, I like that

this is NOS 440ML, microline on aluminum, $240. del'd.

strong separation, tight balance, high output signal, low tracking force

I am playing one like it in my office, also MM, the 540 is the current version, and they make new stylus VMN that fit it

https://www.ebay.com/itm/326880546961?mkrid=711-53200-19255-0&campid=5338381866&toolid=10001&customid=c8e4efaa-d207-11f0-9951-653130323763

When I owned a Rega Planar 3, my brother in law made shims of various thickness in his machine shop for my RB300 arm.  I used 4 shims for the proper arm height with a Sumiko BP Special cartridge ( nude cartridge).  I never ever had problems with the dust over touching the arm.  There was at least an inch or two of clearance. The shims slipped onto the threaded arm base and raised it perfectly.  There is a company whose name I don’t remember that makes shims for the arm, research it.  

$399.

used AT155 body with NOS 155ML beryllium microline stylus, 

https://www.ebay.com/itm/267475997655?mkrid=711-53200-19255-0&campid=5338381866&toolid=10001&customid=213e73da-d20b-11f0-92b0-316562663539

Old Stock? Steve Leung just checked all my vintage cartridges and remarked how amazing it is that the AT suspensions last forever.

review of AT155ML

https://www.hifi-classic.net/review/audio-technics-at155lc-298.html

These look fine and the price is not bad

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