Hey there I am also very interested in multi-modal models, I liked a lot the first two project ideas.

ViT + mBART - Multilingual Image Captioning (WIT pre-train)
ViT + mBERT - Multilingual Visual Question Answering (WIT/COCO pre-train, test on VQA/GQA)

I would love to joing the team, if you wanna know a little more about my background check out my GitHub 1.