I agree to the point that Companies right now are not too keen to spend money on things on which they don't see immediate returns or if they know that this could "wait" & thats one reason why we also put the idea of buying a psychometric test product on hold for a while.
I have a suggestion to make which is no different from what you have thought of.
If you can get certified on Psychometric Test & its evaluation than probably you can develop your own test. You being from the bank while knowing its internal structure can very well define what kind of employees (or personalities) are needed in the bank at different levels & different departments.
Just come across this :
UOWD - News & Events -
See if this can be of any help.Have the name/emai id of the contact person for the MBTI Coursein the end.
-Prashant