Project sounds interesting, and something I would typically look at contracting for, but I’m not sure it’s a <= $100 job. If I had some idea what the ezine will be about, maybe I could get interested in it for other reasons…
Anyway, here’s a bit of free *consulting* to you and whoever gets the bid:
WP-REGISTER.php
The filename change is a minor hack, but you’re looking to collect data at registration WordPress isn’t prepared to accept. This can be taken care of by altering the users table and adding the required columns to it, or by setting up a custom table. The latter is the safer method since it’s not prone to data loss during upgrades, and could possibly be moved into the upcoming users_meta table in WordPress 1.6 (ah, more work!). Still, if this is to be made available in users’ profiles, you’re looking at changes within admin. The need for a public profiles *page* would probably require little more than a customized author.php template, but details on that would have to be worked out.
USER PROFILE
Basically an upload script for avatar graphics would have to be written or modified, as well as hacked (seamlessly) into the profiles page. Key features: size limit, filetype check, automatic file naming (provides additional benefit of restricting users to one upload per). All doable, but seems the largest percentage of the job.
The rest of your requirements are already available through plugins, could be added through pre-existing PHP scripts, or are simple plugins/hacks. So the major aspects of this job are the points I made above.
