I'm not sure why you're not able to take your existing Essential Requirements Checklist and paste in the requirements from the Annex of the Regulations to create a GSPR checklist? This seems like an easy enough thing to do.
If you're just after one that you can use from scratch, then I don't know why you don't just google "General Safety Performance Requirements checklist template." One would come up.
If you're after which requirements under the ER map across to the GSPR, then BSI have a good guide on this (I can't link but just search for GSPR on the BSI site) within its Annex for the MDR. There isn't any guidance I can find for the IVDR.