The add-on package "implicit methods" provides the IAT, BIAT, SC-IAT and the AMP as proposed by the respective literature. While the AMP is based on per-item priming, the IAT variants are based on item-category assignments (incl. feedback) and response times.
I am not sure if I understand your question about "a modificated IAT or AMP" correctly. While the above mentioned questions have some variants and options for refine the settings, they are not meant be be modified largely. Also will the standardized score computation work within the precoedures' limits.
You can enable the package for free testing for 7 days in the shop and try if the question types meeet your requirements. If there are any more questions, please let me know.