Can projects decide on what type of infrastructure setup they need for hosting Issuer Node - decentralized computing (AKASH Network), decentralized storage (Ceramic), etc.?

Yes, they can decide what infrastructure (like other databases, or decentralized store solutions) to set up, we do not prescribe how to do it although it requires more effort from the Issuer side. Nevertheless, in case the issuer decides to choose another infrastructure, we can not guarantee support.