I looked around the pub for the person I'd met in the chatroom, but couldn't find anyone who looked like it.
Literal
Chatroom [at-で] got-acquainted person [obj-を] pub [at-で] searched [but-が], that-like person [topic-は] didn't-exist.
知り合う 'to get acquainted / meet (for the first time)' is the compound verb 知る + 合う where 合う marks mutuality. それっぽい is a useful colloquial adjectival suffix: ~っぽい 'X-like / reminiscent of X,' productive on nouns, adjectives, and verbs (子供っぽい 'childish,' 嘘っぽい 'sounds fake,' 忘れっぽい 'forgetful'). それっぽい 'that-like / like the expected one.'