VPN setup-Not Spiceworks related

Ok, Although I've been in IT for 12+ years, I haven't yet had to set up or deal with VPNs at all. I am confused and overwhelmed and don't know how to proceed.

Point A has a DSL connection. The DSL Router/Modem has GRE capability under port forwarding or I can set up a traditional VPN with SSL VPN, L2TP, IPSEC, PPTP or Shiva VPN. The endpoint is a windows XP client (no VPN Client software-Is there good free VPN Client software available?). LAN is on 192.168.1.X IP Scheme. WAN interface is provided by ISP and is a Static IP

Point B will go through a Cradlepoint CBR450 Router (internet provided via USB Cell Wireless card inserted). It supports GRE or Built-in VPN Termination using IPSEC (http://www.cradlepoint.com/sites/default/files/productdocs/CBR450_manual_3.3.0.pdf). On this side, the endpoint is not a windows machine but plugs into an ethernet switch where pump monitoring equipment plugs into. If this were all on the same LAN point A and Point B would be on the same IP scheme and see each other. Since they are about 30 miles apart, we need to setup a VPN between the two. I set this router up on 192.168.1.1 Scheme. WAN side comes from Verizon (haven't identified if it is static or dynamic)

I don't know if I have even provided enough information for anyone to help me out, but ask a question and I'll see if I can answer it.

Nate