Moving from a Market Data provider to Banking

I've been out of college for approx. 3-4 years now and I currently work in the financial services industry in NYC. I was hoping to receive some advice on making the jump into investment banking (M&A, DCM, ECM).

I work at a market data provider that covers fixed income markets and I've gained a solid understanding of the markets we cover (don't want too be too specific but PM me and I can elaborate). I've also gained a fair amount of contacts in the industry. Also, if it helps I come from a "non-target" and never did a summer analyst internship.

Ideally, I was hoping to talk with anyone that has made the jump from a data provider to banking. I know the first step would be getting in touch with my network and working through referral but in-addition to that what else can I do (that's actually effective)?

Are there headhunters/recruiters that would be willing to work with me? Any leads here would great. How does someone inside the bank view someone with a background at a data provider? vs a newly hired analyst from school?

I'm open to all ideas/suggestions and thank you in advance!