Are IBM WebSphere Portal or BEA Weblogic Portal the best choices for
deploying an online community / personals site / online dating page?? 
What specific portal and portlet components would be necessary to
implement such a site?
Features to include: Users create unique IDs, create profiles, browse
databases of other users, send messages to users, automated emails
notifying users of 'matches' between profiles, etc...
Could this site be built over any database (DB2, Oracle, SQL) or is
one preferred?

What small/medium development companies in the Northeast would be
suited to creating such a site?

Hi, the best thing to do is install apache webserver (free) and MySQL
server(also free) and PHP interpreter(free) and get a copy of PHPNuke
from http://phpnuke.org If you are stuck in installing any of thse i
may help you.

WebLogic Portal does all of this and has a very easy to use
development environment called WebLogic Workshop. It works over any
database. There are a bunch of companies that could help in the
Northeast, NESS USA is one. You can also download WebLogic Portal for
free at dev2dev.bea.com

IBM websphere and weblogic are too expensive. It seems like you want
to develop your website using J2EE. Resin (www.caucho.com )(very
cheap) has pretty much all the features one will need a portal that
you are trying to implement. Tomcat, which is free can also be used
with success. Its free, and no support.

For database, I would recommend postgresql, because it is very fast
considering it is free, and it will even compete with oracle etc. if
the need for clustering and a HUGE application is not there. Mysql as
a database server will do the job also, as you can buy support for it.
It is also very fast but lacks a few features.

I will not trust offshore companies , or companies with limited
experience with this project. Small companies are ok if they know what
they are doing. Without a good person who can lay-down specs very
precisely for offshore developers, it is very easy to get really bad
work done.

Performance suggestion: Local CMP beans are ok, Remote CMP beans are
too slow.  Get an analyst who can do the performance planning for you,
before the project even starts. It seems like your website will hit
the database pretty hard so you make sure someone developing your
website has experience writing database intensive websites.

http://www.desiest.com is example of a website which is very databse
intensive and uses resin.

Paul