accurate circular velocity measurements of the stars in the galaxy
a decent luminosity profile for the galaxy
some analysis which looks at the discrepancy between the two
The Milky Way seems to have been studied a lot, with decent mass models (e.g. McMillan 2011) and circular velocity observations (e.g. Eilers 2019 which includes mean observational data actually tabulated rather than graphed) is readily available.
What I'm wondering is which other galaxies have this kind of data? Or indeed at least have decent luminosity profiles & circular velocity observations even if the halo has yet to be analysed.
To my knowledge, strong gravitational lensing models exquisitely constrain the distribution of a galaxy's total mass (which is mostly dark matter; on average about 85%, if I remember correctly). Studying those systems would allow you to find the best mass profile of the dark matter halo and some parameters, such as the halo radius. Moreover, if the best lensing models are those relative to galaxies showing Einstein rings, I would consider those systems. In particular, I would consider data from the JWST. Here you can find some HST examples of rings (in bluish colors) around bright galaxies (in reddish colors): https://www.nasa.gov/feature/astronomers-revisit-first-einstein-ring-in-archival-data