What are you trying to accomplish with a VPN connection?
If you want secure access to devices and files on your home LAN then you can set up a secure VPN server on your router.
If you want to surf the web, check e-mail, etc. from insecure public WiFi access points then you need to run VPN on your smart phones, laptops, tablets, etc. when you connect on public access points. Figure on spending $6 - $9 a month for a VPN service. The cost varies depending on how long you sign up for, VPN features and how many devices you want to connect using simultaneously without running the VPN on your home router. Depending on the device and its processing power you probably will experience a 5% - 10% reduction in throughput.
Finally if you want to run a VPN on your home router that will allow all devices connected using the router then you can do so using a VPN provider for $6 - $9. Depending on the VPN provider and the type of service you sign up for you also maybe able to connect some other traveling devices at the same time your home router is connected to the VPN provider. Running a VPN on your router can result in a 25% reduction in throughput. with a less powerful router such as a 54G the reduction could be even worse.
As for VPN providers I have tried and you might want to consider are: StrongVPN, IPVanish, Astrill and HideMyAss. HMA was the slowest and most aggravating to use. With the other three there were trade offs in speed and features.
Good luck.