First marathon plan for someone with strong cardio base

So I’m at a bit of a loss for what plan to select for my first marathon. I’m in good shape and started running consistently (after taking years off) about 3 months ago. I ran a 5 mile race recently and finished with a 7:12 split, and I think I probably could have hit 7:00 if I wasn’t recovering from a cold.

I’m about 20 weeks out from the marathon so have a couple weeks till I start an 18 week training block. I was considering pfitz 18/55 but I think the volume is just too high for me. I don’t think I have the musculoskeletal adaptions to handle such a high training volume. I don’t want to injure myself. Just took a look at Hal’s intermediate 1 and I thought that looked more appropriate?

Tbh I’m not even sure what my goal pace should be. I loosely settled on just going for a sub 4 since it’s my first although my friends tell me I should shoot lower given my current fitness level.

Just looking for some advice for some someone who has a good cardio base but hasn’t built up the weekly mileage to handle a high mileage plan