Firstly, I would recommend to look through this site: https://www.pcisecuritystandards.org/ You'll need PCI DSS Level 1 verification as a payment processor. With this in mind you'll need to start making an infrastructure for your venture.
We got the web designers working on the pci compliance and all security measures. However it seems like we lack some information about the system's working procedures and this makes our business plan look unprofessional. We can't make a proper financial plan due to not knowing the costs exactly.
You'll need a good team of web-developers, which can make integrations with the banks, and also you'll need a person who understands in credit cards anti-fraud management. In other words, you need a good team in first place and then a business plan.
BTW, do you have any estimates who your potential clients are? It is better to have some clients portfolio before launch. Too many IPSPs have launched recently.
We do and all of them are local companies which don't use any payment processors. PayPal holds only 1% share of the online market in Turkey at the moment. We are in good contact with some of those clients so I believe we'll come to an agreement with them easily.
Are you going to provide merchants with MIDs in banks? Or you are going to provide processing and aggregation services to your clients? If you are going to register MIDs you'll need god relations with the banks as well.
You want to be a payment processor but you don't know where to start and you ask for help on a public forum! Yeah right, good luck with your venture! Do you have a clue at all about the costs, staff, knowledge and other security issues you need to sort out!!