These might be the ticket - 8 gauge, 5 inch, luer lock stainless blunt needles:

https://www.amazon.com/dp/B0799DX775/ref=cm_sw_r_cp_awdb_t1_8ou9EbK4T53TH

And this is a link to the 30 mL syringes I ordered for another project:

https://www.amazon.com/dp/B07PHQMH8V/ref=cm_sw_r_cp_apa_i_esu9EbCQGZW95