Most times, the data you need for building personas is available from secondary or tertiary sources (tertiary data source means you take somebody else's personas holus-bolus). If team members or vendors are telling you that specific research is necessary, then they're ahead of themselves - they're getting focused on "how" rather than "who".
Here's a link to an example persona we built for a social media play: example persona. Notice it has three components:
- the profile, where we apply some demographics and technographics so we build a picture of the person;
- the schedule, where we try to provide a context for the profile;
- the word picture; where we add some comments to "round" out the character and give life to the psychographics.
And please, before any comments, recognize that this is a very stripped down version designed to give you an idea of what might be included. For our Flex build in 2005, we developed eleven of these personas - all from secondary data - which we later informed with UX research. Each was about 1mB.
Why personas? Go back to the methodology - the most important component is understanding who you're building this for. Getting a picture of them that everyone can share is vital.