Microphone FX Inject Stage Box Project

Hey there,
I’m trying to design an interface that would allow me to plug a standard dynamic mic (sm58) into several guitar pedals.
The interface would consist of an input stage, matching the impedance to guitar pedals (like the shure line matcher). then an insert section, like on a mixing desk, allowing the mic to go through an fx chain. Then, 2 Aux lines allowing to send the mic into 2 aux lines (in parallel) like a reverb/delay.
Then, a mixing stage to mix the effected mic with the 2 return lines.
Finally, a DI output section that would bring the signal to line level and balance it.

My first wonder is, how would i match the mic impedance (approx 300 ohms) to the guitar level ?
I see the shure line matcher transforms form 300 ohms to 40k so that would be a first idea, but what are the other options than transformer, as this would be an active circuit ?

If any of you have any advices to give on this project, that would be awesome.
I’ll be updating the progress on this and, if it sees light, it will be open source.

Peace !