Calls from BTS to PTSN planification doubts

Hello, my name is Diego. I've a configurated sysmoBTS in OpenBSC network-in-the-box (NITB) mode, and the osmo-nitb is working fine, doing and receiving calls and messages between the phones connected to the sysmoBTS network. At this point I would need to call outside the OpenBSC, and I would be very gratefull if someone could help me with some doubts I have. I'm new in this. For the isdn card capable of NT-mode, I've seen the "OpenVox B200P 2-port ISDN BRI PCI" card for buying, but: 1-An "OpenVox B100P ISDN BRI PCI" card, with only one RJ45 female connector, could be used correctly, working together with an already installed PCI Ethernet Controller card? Or, is it better an isdn card with two RJ45 connectors in the same card? One for connecting the BTS to the computer, and the another for connecting the computer to a LAN through a router or switch? I would like to avoid to cut cables as the LCR guide says, http://isdn.eversberg.eu/download/doc-1.4/linux-call-router-1.4_1.pdf, and the problems with the cross over and not crossed cables. 2-The "Howto OpenBSC with Asterisk and LCR" guide, http://openbsc.osmocom.org/trac/wiki/OpenBSC_LCR, indicates that it's necessary compile and install LibOsmocore and OpenBSC, but the OpenBSC/OsmoNITB inside the sysmoBTS is working, so I'm not sure about this step. If the solution is to build, configure and run OpenBSC/OsmoNITB + OsmoSGSN + OpenGGSN on a PC and configure the sysmoBTS to connect to this, should I change the image of the BTS and its whole configuration? 3-Although I don't have the isdn card yet, for testing some configurations in the PC I followed the "Building and Running OpenBSC with Asterisk" Pierre Kim guide, that I believe is newer than the "How to OpenBSC with Asterisk and LCR", and I haven't problems with the installations. So if I run the lcr: # lcr start ** LCR Version 1.14 LCR 1.14 started, waiting for calls... and running the osmo-nitb: # ./osmo-nitb -m -P DB: Database initialized. DB: Database prepared. My question in this point, is it only necessary to connect the BTS to the isdn card with the right OpenBSC to finish the system configuration? Many thanks for your time and for your work. Kindest regards, Diego.