Personally, I'd rather have plainer — or should I say, more understated clothes.
Literal
Me-style [topic-は] more plain, or-rather refined clothes [subject-が] want-but.
僕的には borrows the ~的 suffix and attaches it to a personal pronoun — a casual, slangy construction meaning 'in my opinion.' ってか is a spoken contraction of というか, used to self-correct mid-sentence. 地味 (plain/subdued) and 渋い (refined/understated with connotations of mature taste) are both aesthetic terms, with 渋い being the more nuanced choice. The trailing ~んですけどね softens the whole statement into a mild aside.