I ran modified 103R’s for about 5-6 years and about 6000 hours a number of years back before moving on to other (retipped cartridges). The ones that I spend the most time with were in aluminum and ebony bodies (as opposed to "housings" which I take can actually mean a true replacement body or something that actually envelops or wraps around the Denon plastic body, which I would not be inclined to use).
I also had a clavellin bodied 103R, which I definitely did not like as much as either the ebony or the aluminum body, both of which sounded very nice and actually quite similar. By comparison, the clavellin body sounded a bit thin and hi-fi-ish.
The modified 103R’s I used were retipped by Peter L at Soundsmith, two with his standard line contact on ruby cantilever and the other with his top of the line OCL on ruby, which was a bit of a bear to set up, but if properly dialled in would offer just a bit more detail than the standard line contact. Not sure if it was worth the trouble.
As I said above, I’ve moved on to different cartridges in the past 4-5 years and have also had both Andy and Steve L do cartridges for me as well. Andy did a couple of Ortofon MC 20 Supers for me, one with boron/microridge and the other with sapphire/microridge, and he also installed a Namiki cantilever with MR (which I provided) onto an Accuphase AC 2 for me after those Ortofons.
More recently Steve Leung installed a couple Namiki Boron/MR cantilevers which I provided him with onto an AT 33 Mono and a SAEC C1. I wouldn’t hesitate to deal with either Steve or Andy in the future; they both did very good jobs for me, as did Peter at Soundsmith. Andy is the king in turnaround time though in my experience if that matters to you.
In the end, I really liked and preferred my aluminum bodied 103R-the ebony was also very good but I ultimately stripped on of the mounting threads on it, which is the drawback of a wood body without metal threads-that will never happen with an aluminum body.
With my experience with modified Denons, I would not personally want to run one that was partially nuded, and or continues to utilize the Denon plastic body in any way.
And ultimately, I’ve come to the conclusion that I prefer boron/MR to just about any other combination of cantilever/cartridge out there after running most of them.
So my preference, if I was in the OP’s shoes, would probably be the ebony body (as long is it’s not wrapping around the existing Denon plastic body, which IMO should be removed completely) with a boron MR. Or an aluminum body (they’re often available cheap on Ebay-cheap being in the $60 range) with boron/MR.
Will require a good phonostage, and the Audiomods arm can be beefed up with headshell weights from the manufacturer I believe to increase effective mass into territory that a modified Denon will like.
A properly modified Denon 103R or 103 with a good body and high quality cantilever/stylus is a pretty nice cartridge and does a lot of things well and some things exceptionally. IMO it will probably be extremely competitive with many new cartridges priced into the $1000-$1250 range.
The price of new cartridges has become ridiculous, along with a lot of other audio items, in the past 5 years or so.
For the OP, at $560 for a modified Denon all in with a boron/MR combo, as long as you have the right tone arm and phono stage, it is going to be a very good value and easily good for 1200 hours if handled well and not abused.