Probably Pulumi
Terraform is ugly but it works well enough for me and seems ingrained enough to be durable to this kind of thing (i.e. I bet for sure the community would pick it up (I wish I could say that I'm part of that community but I can't say I use it quite that often))
This is clearly a business decision rather than technical.
Pulumi is meant to be semi-automated (in generating the bridges) so perhaps is slightly better off in maintenance.