Don't get a Planet Card. There are a number of considerations for you to address, not the least of which is it is very difficult to have a single ISDN connection BOTH handle your incoming calls from ISDN equipped BBS users AND do your connection to your ISP. I would order a 4 channel ISDN instead of a ISDN (one is a primary rate interface and the other is a basic rate interface) and use a Pipeline 130 (which can handle up to a T-1 connection). That way you will have one set of channels able to call your ISP on demand and the other set of channels answer calls from your bbs users.
You would have to reconfigure your arrangement a little in that you would need an Ethernet hub and an Ethernet adapter for your Centris 610 (actually, you might need an Ethernet card for your 610, as some of the 610's didn't have ethernet), because the Pipelin 130 is an ethernet device. So, in essence you would be creating a mini-ethernet network in your house or office) for your bbs.
You also might want to think about dedicated ISDN service for your BBS. Dial up 64K ISDN is about $50 a month and dedicated is only about $100. So, for $50 more you get 100% connectivity.
Email me if you need some more help.
Matt Snider, Executive Director MidCities Macintosh and Newton Users Group MUG Central BBS (bbs.midcities.com) mrmacman@midcities.com
