Rosomak is the Polish name for license-built variant of Finnish Patria AMV 8x8 Armored Personnel Carrier. More than 900 of those were built in various variants for the Polish Army. According to Mateusz Morawiecki, the contract to supply 100 Rosomak vehicles was agreed with Ukrainian PM Denys Smyhal and those will be paid by EU and US funds.
For now, details for this contract are quite scarce. Sebastian Chwałek, president of the PGZ Group, a parrent company of Rosomak SA, said in a television interview in Polsat News that those vehicles can be delivered in various variants. It is understood that final configuration has not been agreed yet. Depending on the specific arrangements, Polish industry could deliver manned and unmanned turrets for Rosomak APC armed with 30 mm guns, as well as Remote Controlled Weapon Stations with machine guns and specialist equipment (MEDEVAC, recovery, C2 etc.).
There was also some speculation on Ukraine being provided with Rak self-propelled mortars (developed by HSW, a PGZ, and featuring the TOPAZ C2 system proven in Krab howitzers used in Ukraine). Fitting at least some of the APCs with Rak mortars could be a welcome option, since the system is in serial production for the Polish Army and is already quite widely used (and appreciated) by Polish Army units.
On the other hand, Australian EOS company has revealed that it has received an order for a delivery of up to 100 of its "heavy RWS to Ukraine, including spares and related services", with an Ukrainian company SpetsTechnoExport being an ordering party. The deliveries are planned in 2023 and 2024, and the number of ordered RWS is similar to the number of vehicles announced by Mateusz Morawiecki. EOS has various Remote Weapon Stations that could potentially fit on Rosomak, including R400S used on the Bushmaster vehicle donated to Ukraine, as well as heavier R600S and R800S, capable of handling heavier weapons up to and including 30 x 173 mm Bushmaster II guns. As of now, however, there are not many public details of the agreed deal. Perhaps during the upcoming Wednesday visit of Ukrainian president Volodymyr Zelensky to Poland more details will be revealed.