tap, tap... is this thing on? Wrangling membership databases

I'm wondering if anyone out there has input on software for wrangling a Guild membership database.

Our guild hovers at about 100 members. We have a WordPress website (wssaustin.org) that works wonderfully, and currently use GroupSpaces for membership database wrangling and payments, and Biblionix for our library catalog.

We would very much like to move away from GroupSpaces, and would also like the membership database and the library users database (although not necessarily the book catalog) to be integrated. We're loving taking memberships online and want to keep that. 

It seems that we should be able to use Wordpress for the membership database wrangling with a plug in?  I've had "Contact form 7 in conjunction with Contact Form DB"  recommended to me as well as WP Estore and WPeMember .  But wonder what other people's experiences are before investing money and time in learning them. 

Or maybe there's a non-WordPress solution. Just not ExCell or Google Docs! We've been through that.

Like most guilds, we're  not a terribly well-funded group, so we do things as much as we can with volunteers.  I can tweak WordPress and designed/ set up our current site, but I'm not a programmer. Other people in our group are less technical, so simplicity or a good UI  is important. 

 

Thoughts? Recommendations? Ideas?