Jupiter, Saturn, Uranus, Neptune system GM I'm modelling the solar system. I'm using data from Nasa.
To do this I'm using the barycenter of the planets Jupiter, Saturn, Uranus, Neptune. However the website fails to give the Gravitational Parameter $\mu$ for these barycenters, even though it does do so for Pluto's barycenter.
To make matters more confusing, the $\mu$'s given at Wikipedia are slightly different, though I assume these are just out of date.

So I'd like to know if there's an as up to date resource as possible available for these parameters. Paywalls should be OK as long as they are of major publications.
$$\frac{\mathrm{AU}^3}{\mathrm{M}_\odot\cdot\mathrm{day}^2}$$
-form also good.
In the JPL report on ephemerides DE430 and DE431,
on page 49, table 8 gives the mass parameters they used for the major planets.
They cite the
IAU 2009 system of astronomical constants.
There may be newer estimates, but to verify your own simulation against HORIZONS, you might as well use the same constants they did.