will i need the raspberry anyway?Look at the ISP's Router manual and find out if it can be set as Modem only (you can call the ISP and ask too).
If it can configure it as a Modem and get yourself a Nice Wireless Router that can do VPN.
No you will not. Most midrange to high end home routers support that feature already. (ASUS 6x series wifi routers, for instance.)will i need the raspberry anyway?
No you will not. Most midrange to high end home routers support that feature already. (ASUS 6x series wifi routers, for instance.)
The only thing you need to do is make sure that the router supports the VPN protocol(s) you want to use. (There's only 2 or 3 in common use, primarily OpenVPN, and most devices support all of them, but it's important enough to double-check.)