So, you haven't even heard the thingy. Have you heard a Denon DL-103 on a friends system?
Any MC on your system? I hadn't, had to make a choice based on research and advice.
1st you said Rock, then Jazz and Rock.
My instinct: get the DL-103 going with advanced stylus shape on aluminum, for 'not too much' money, use/hear it, keep it as your base and compare future considerations to it.
I talked to Steve at VAS when I had the same idea as you: buy one broke, fix it, save money. He gave me specific advice when I found opportunities, usually involving potential complications ... I decided to get new.
My first MC is AT33PTG/II (check stock of anything these covid days)
https://hifiheaven.net/shop/Audio-Technica-AT33PTG-2-Dual-Moving-Coil-MC-Cartridge?language=en&c...
to my surprise, in addition to sounding great on my mostly Jazz, it can rock! Santana, War, Rare Earth ... and electronic stuff like Eurythmics, Blue Nile. Slide, banjos: Dicky Betts, Rising Appalachia, Larkin Poe! Violins: check. Piano: check. Stand-Up Bass: check! Drums: check.
Next, my friend gave me a NOS Goldring Eroica LX.
https://www.goldring.co.uk/goldring-eroica-lx-cartridge.html#tab2
I have it on my 2nd arm, so I can compare to the AT within seconds. Less separation (can be beneficial), the special Gyger II stylus shape is rare,
sounds great
So you have called out a few things and given me a lot to think about. I have never heard a Denon 103, and for that matter I have never heard a MC on my system. Just to set the stage I currently have a Sumiko Moonstone I am running and want to step up to an MC. I have a limited budget and looking for something that will match the money I spent in a TT and Tonearm but I have to start somewhere and I want to try an MC. So I need a base but I would like to find a base that gives a lot for the money. There are a lot of people pointing to audio technica and I am starting to think it may be a good place to jump in before I start buying like crazy. I still will have the 103 and the ebony housing that I can upgrade after I get used to something.
On Music I am 80% rock and 20% jazz but the jazz collection is crowing every day!