Over the years I have tried many diferent combinations and configurations of VPN.
The first problem, you have hinted at... Safety. - Do a risk analysis,
if you can't do one or don't understand the risks - don't do it (by
that I mean remote access).
The next problem is speed and latency - That can be overhead from
supporting a VPN tunnel, to trying to run it over too 'thin' a
connection.
Finally security - Obvious issues (hopefully) - do you really have to
do it, is there no other way to perform the required functions -
dedicated link.
My best effort to date has been with ADSL/DSL 128Kb/s
Cisco PIX 500 firewalls (I don't like Cisco, you have to be 'in thier club to play' - but its fairly solid) to support the VPN and
VNC to interact with the system.
The above configuration was fairly solid as it was all off the shelf
stuff, definately steer clear of WiFi router stuff (probably WiFi as
well) especially Cisco's sister products the
Linksys
stuff. That might make me unpopular but in my experience if you don't
clear the log files every 10 minutes it locks totally, WiFi locks
........ (despite constant updates and so on) and so on.
Microsoft VPN stuff has worked but in the past but it has and could
lock the machine running VPN totally bit annoying if you have to drive
50 miles to solve the problem, perhaps it's better now