I also have the PLX-1000 with an azimuth adjustable Jelco HS-25 headshell. For the money, it’s definitely a contender versus the Technics. The Jelco headshells are getting harder to find as new since Jelco stopped production last year.
To stay under $1000, you’ll need a cartridge below $300 as the PLX-1000 goes for $700. I use the $240 Ortofon 2M Blue and have been pretty happy with it. The Jelco headshell is about $60, if you can find it. Pre-mounted on an Ortofon SH-4 headshell, you can find the 2M Blue for $270, but the SH-4 is not azimuth adjustable, like the headshell included with the PLX-1000.
For something a bit above $300, the Nagoaka MP-150 is priced at $323 on Amazon today; it’s a widely well-regarded MM cartridge. The MP-150H is going for $406 today, pre-mounted on a Nagaoka headshell. I would have purchased a Nagaoka MP-110 or MP-150 if I had not owned the 2M Blue when I bought the PLX-1000.
My next upgrade from the 2M Blue will likely be the Hana EH at $475; a high-output moving coil (MC) cartridge. I have the Hana SL on my VPI turntable and I really like it.