I’d get CFI done first. Reason being that the sooner you can get your instructor ticket, the sooner you can start applying to CFI gigs...which seem to be the best option for a low-time guy these days...albeit still hard to find.
If it were me, I’d fly the Duchess. It’s commonly used for ATP training, so you may see it again, and learning the ins and outs of the 430W (those things are absolutely everywhere) will serve you well. Being well-rounded as a pilot is a good thing—knowing nothing but glass isn’t.
Just my $.02