10-team 1PPR league with 2 QBs and a flex spot (RB/WR/TE). We get to select up to 4 keepers.

I'm already keeping Cousins (11th round) and Goff (10th round).

Options for other keepers and where they would be drafted are:
Jay Ajayi (10th)
Will Fuller (16th)
Marvin Jones Jr. (16th)
Dion Lewis (16th)

If I kept 2 players that would be 16th rounders, one would be a 15th.

I have the first pick so I will end up with Bell, Gurley, Johnson or Elliott. Originally I thought Ajayi was going to be a keeper, but now, not so sure.

I also have an offer on the table for my first round pick for the 7th and 27th overall picks. I'd have to throw in a late round pick to make it even. I'm trying to work out something similar with the 4th overall pick so I can get one of those RBs listed above.

Looking for some input.

A bit of uncertainty with all of them, considering the RBs are in committees and the receivers seem like they are TD dependent for the most part. My takes, dependent on what you are looking for.

Safer picks: Jones Jr. and Ajayi. Lewis and Fuller have an injury history. Lewis is more of a specialist.
Value picks: Jones Jr. and Lewis. I don't think Ajayi is worth the six round differential with Lewis in PPR.
Potential Upside: Ajayi and Fuller. If Ajayi blows up, he could become a feature back and Fuller has shown high value with Watson under center.

I would lean towards the value picks. I would be okay with starting Jones Jr. at a WR#2 and at least you are certain in what you are getting with Lewis, while giving up 15/16 round picks.