I'll go with internist (though we don't seem to have those in the UK) or a geriatrician even though most of us are younger.
I think a doctor who can handle complexity and multiple symptoms is best and geriatricians should be good at this as older people have lots of different things wrong with their bodies.
There should be some middle ground between primary care generalism (no time and no access to tests) and the super specialism (too focused on a single organ) that you get in hospitals.