Revival Questions

I've got a fairly fresh roller cam 408-410 Magnum that has sat in a truck for about 5-6 years since, I last drove it or turned it over. So far in asking and research, I wanted to double confirm some things. My goal at this point is at least to get the engine to turn over with the starter. I don't have the fuel system hooked up so no worries there.

With the length of time that the engine has it appears I need to pull the plugs and squirt something in the cylinders to help. I'm assuming Marvel Mystery Oil would be best?
The other question I have is I see there is a couple different priming tools out there. I see the MP Mentioned a lot and then I see the 440 Source Deluxe tool. I'm just wondering what tool would be best as I also have another project with 440 in it as well. Link for the Deluxe Tool to what it looks like. DeLuxe Engine Priming Tool.

Two other things I will include is that the truck I believe has maybe a Milodon HV Pump? and Milodon Oil Pan. The oil it uses is Brad Penn 20w50. Ironically, I changed the oil in it back about 4-5 years ago and hasn't even been ran since then. Anyways, I'm just looking for any additional information or tips that might be helpful. Thank you in advance.