I am looking at building a TF Piper Arrow as my next big scale project. (I wish I could get my hands on a Bonanza[

])
I am wanting an engine that fits completely in the cowl. Looking around at build threads it seems like a 91 4 stroke sticks out of the cowl.
What can I get inside the cowl? Would a twin be a good match for this plane. Something like a saito 100 twin or an OS gemini 120 twin be a good option?