I understand that the market may not be good now, you just need to bite the bullet and find the roles. Good roles don't come easy. I have a masters as well, and getting a contract role for yourself is not justifiable.
Well, agencies will always sell the roles by saying its top tier bank etc..But end of the day you are still a contractor. Especially in the banking industry, roles are in contracts for a reason. Don't think about conversion, renegotiating salary at the end of it, because it's not certain. Your contract may be renewed or else you have to join another company. Rep of the bank is important but not everythng. I rather you have a perm role in a lower tier bank with good learning curve. Another view is that it does helps in your next employment if you work with a top rep bank, but that is provided you stay long enough to gain the experience. If you say you can move to a better position just because you had 6 months experience in a top rep bank, this is not well perceived by employers.