VPN using 1751 Routers by Cisco

[abauche]

In My Company we are trying to connect the two branch offices located in diferent States,we want to connect the two lans in one, we heard that the VPN is an Excelent solution, i was reserching a little about VPN´s and i heard that the Cisco 1700 series routers are a good option for VPNs i research a little more about the models of the 1700 series and i think that the 1751 router is the best option because in the Future i will probably include some VOIP features to the office.

Here are my questions:

1.- Can i Use two 1751 Cisco routers to create a VPN , because i heard that i need a cisco 3000 VPN concetrator or something like that.

2.- In Each office i have 25 users , the cisco 1751 router can handle this amount of users

3.- How difficult is to set up a VPN with two routers only , i configured software VPN and that was easy , but i want to know how difficult is to do the same with Routers.

4.- If i have a 512 kbps Public Connection (not behind a firewall) in each office , the VPN encriptation process will not slow my LAN a Lot.

5.- Someone know where can i find some info to do all the process of the VPN with the routers a book like "Making a VPN with cisco routers for dummies" or something like That

For all the people that can Help me Thank You .......