Model C maintenance/Upgrades newbie, help PM3 Monitor (wanted)

[candiankid]

Just picked up a used concept 2 model c this morning. It has the PM2 monitor on it.

What are suggestions and some of the things I should do to bring this machine "up to date"

1.I am for sure wanting to upgrade to a PM3 monitor, anyone got some suggestions on where to find one?
2. The chain is rusty and based on the research on this forum there is a kit I can buy to replace and oil up?
3. I've also read I can do something to the seat to make it quieter.. if someone can shed some light onto that
4. Saw a post a few months ago that the model D seat is different and could also replace that

[Citroen]

You don't want a PM3 (they stopped production in 2014). A PM3 doesn't have any features to easily connect to your phone or your digital HR strap.

You want a PM5 and the best option for that is buy the PM5 & retrofitting kit from https://shop.concept2.com
You'll also be able to get a new chain from the shop.