I think there are a couple of easy tweaks that can past Constitutional and political muster.
One is to limit MOCs ability to fund raise while Congress is in Session. You can't really regulate it the other way around given SCOTUS rulings on campaign contributions as free speech, but you can do it this way. There was a great column in the Washington Post about this very matter:
http://www.washingtonpost.com/...9-2cd6fa8da5c4_story.html .
Rather than pay less, I would seriously try to increase staff pay. The real revolving door is Congressional staffers. They come to Washington with big hopes and dreams, advanced degrees and tons of student loan debt. In return, they get long (and often weekend) hours, maybe $35,000 a year to live in an expensive city, and very little recognition. Promotion for them comes from either ass-kissing or being damn good at what they do and even then, the pay is subpar to what they would earn working for the federal government, let alone private entities. Then everyone acts so surprised when a legislative assistant on a key issue for a few years suddenly decided to quit and join a lobbying firm/association/etc and triple or quadruple his or her pay. I think you could keep half of the staff by simply paying comparable wages to federal government workers along the same education/skill set wages. Otherwise you are stuck with the revolving door, or worse, the trust fund babies looking for fancy titles who are the only ones left able to afford working on Capitol Hill.
I'm not sure money in the form of campaign contributions is quite as powerful as it used to be and I've seen it from the inside plenty. The reality today is that you can leverage dollars and social media to generate as much or more buzz than paid media. People fast forward through commercials, ignore banner ads, and using the mail, ha, good luck. So instead the real value is in peer-to-peer relationships, moving or becoming what everyone is talking about, and reaching your electorate where it hasn't been reached before.
Multiplying the number of legislators will never happen because it requires Congressional ascent. UNLESS you can get it through Constitutional Amendment. Even if you did, i'm not sure where they would meet. Or how they would be staffed. And I don't think you diminish special interests power. Quite the contrary, I think you increase it because now less money is needed to take down an enemy or prop up a supporter. Independent Expenditures gain in value.
Enough from me.