I've done this research before, and earlier this month posted a similar note on state senators. State representatives have the option of making their office expense reports public, what they spend on rent, postage, staff, etc. A list of state reps who do this are listed below.
I started with list of members of the PA state house from the state's web site, then used the caucus pages (www.pahouse.com, www.pahousegop.com) to find links to each state rep's page, then went through clicking on each link. I scanned the links on the home page, and looked at the subject categories on the menu bars, mousing over them to see what options, if any, were on the submenu. It is possible that expense listings are buried further on a site, but, honestly, if it takes more than two clicks to find it people aren't going to drill down far enough to find them.
Most state reps who list their expenses do so for months or years, some provide reports for all years they have been in office. It is impressive. Others list only the current month. A few are in a separate "partial" category -- people who have some reports listed but aren't current.
As a Democrat I find the party distribution disheartening. In this regard, it is clear, the Republicans are the party of transparency. C'mon, Dems!, get it together and post your report! It is also disheartening to see that some state reps I think very highly of don't make their expense reports public.
I make an effort to provide the due diligence necessary to provide accurate information. However it is always possible that I missed something or made an error. If so, I apologize.
Here is the list of state representatives who make their expense reports public: