Best finance job for government exits?

Might sound like a stupid consideration but I'm interested in going into government as a long-term career option but am interested in finance in the short-term as a post-grad job (or potentially long-term depending on how much I like it). Are there any fields within finance that are especially helpful in terms of skills/knowledge gained/network built (would PE v. IB v. ER be more helpful, for example) besides specific coverage groups? Are there any firms that focus on government transactions/deals specifically? Any input would be appreciated.