DMARC shouldn't be an issue for mailing lists, as long as one of DKIM/SPF passes. Are you seeing reports of both DKIM and SPF failing for mailing lists you use?

Properly configured mailing lists shouldn't modify contents of emails causing DKIM to fail.

I personally use Linode and would recommend them. But basically any tier 1/2 provider, i.e. too big/popular to block, will do. However, I would avoid DigitalOcean per my experience due to them completely blocking SMTP on IPv6 in addition to badly implemented IPv6 support and seemingly subpar support.