"Off the shelf" requests for specific devices make for shopping questions, which are forbidden, but it's ok to ask what the name of such a device is. In this case, "Power Factor Load Bank", "Resistive/Reactive Load Bank" or separate resistive and reactive banks will work for you. They look expensive.
A large inductor has a terrible power factor. A resistor bank in series with an inductor has an arbitrary power factor. You can buy or build an inductor or build your own heater to use as a resistor bank of arbitrary resistance and power. A fan for the heater can either be separately powered or contribute to the reactive load.
If you have an arbitrary power level, you can calculate an inductance/resistance combo with ample current rating, reasonable size and correct power factor, you can parallelize it to achieve the desired power level. An inductor is just loops of wire on a core of desired permeability, and a heater is just wire (in your case with a small temperature coefficient looped back and forth to achieve desired form factor, so both can be made at home, especially if you have a suitable place to go junk diving for transformer cores in particular, either an ample size one to get you started or a number of smaller matching ones like doorbell transformers. Already wound transformers wouldn't be good inductive loads for you as their inductance is so high as to limit no load current and losses to a small % of full load value, although that small load has low power factor (0.2 was the number I found for a transformer with 3A no load but not from a datasheet), you would need huge transformers to get significant currents. Putting the right size series resistive load on the primary and parallel resistive load on the secondary would allow you to either use maximum power at an arbitrary power factor, or produce a lower power at same or lower power factor. The power factor of the load is transferred to the primary, so there's no reason you can't incorporate a transformer, but there's a limit to how much you can load it and have it still contribute to lowering power factor, even with reactive loads, as the loss increases due to reactive currents are true power.
Calculating the resistor sizes for the input and output heater banks could be difficult though if you wanted to build the heaters in one shot without multiple taps. The necessary transformers may still be huge. On the other hand, a single wind your own inductor on a doorbell transformer with appropriate series heater would be much easier to calculate and give you an idea of how large a modular design would have to be for a desired power level. You would want to aim for 10% more inductance than you think you need, and use the largest size of wire (or parallel set of wires) you can wind the appropriate number of turns with to maximise the available power factor ratio of the inductor you create. Again, a big project to calculate, but easier and you can produce experimental estimates at a low cost.
If you prefer, you can make tapped inductors by winding single or inductors with layers stacked before adding a new turn to the core. Use large wire on a rod, toroid, or regular core. Cement the windings in place (I can't remember the product for this but you can look it up) and on one side of the winding, file a flat face of exposed conductor along the path of the tap arm.
Either inductors or heaters, if designed to exceed the target value, can be adjusted down by removing turns or length.
One last thing, be very conscious that your power company may be quite displeased with you connecting large low power factor loads to their grid, and they may reflect that in their billing. For a large building to blow power factor, the cost can be in tens or hundreds of thousands of dollars for a single event.
