though it wouldn't totally surprise me to see something that is a bit more of an outlier, like new 125mph Desiro Citys with a higher spec interior for the Trent Valley services.
The 125mph Civity (as being produced for TPE) is another option. It's also rumoured First Group are looking for a solution for them to be able to run at up to 115mph on the WCML despite being non-tilting.