Does the coil's winding material matter?
The magnetic flux B of a solenoid with one layer of windings is expressed as: 




μ: Magnetic properties of the core
N: Number of turns
l: Length of the coil
I: Current through coil 


μ is constant (at least in theory), coil resistance has no part in this equation, and all other parameters in the equation remain the same as you state, except for the current I. 

The magnetic flux is therefore only proportional to the current flowing through the coil. 

Nevertheless, a higher specific resistance of the conductor material results in a higher overall coil resistance, which in turn requires a higher voltage over the coil's terminals to produce the same amount of current.

Although the flux B for other coil configurations is expressed differently, resistance has never a part in it. 

There is also no correlation between material density and electric resistance.