Looking on to offer PPTP based VPN service (128bit crypto).

AIM: Something as simple as Relakks. Just enter username/password and click create.

Required:
- Which PPTP server to use? PopTop seems to be my option right now.
- But I think (and assume) this is a command line only app, running as a daemon, so I require a web based utility to manage the whole network. Any ready made software?
^^ If not, any one or any place I contact to have this custom made for me?

If you have any other tip or a trick, do let me know. Will be helpful :)

PS: We are going to use PPTP. No L2TP, IPSec or something else - avoid recommending that point, please.

Why not just use pptpd in Linux? Can't get any cheaper and it is fairly reliable (not as reliable as OpenVPN but you aren't interested in anything but pptp :P )

Well, the setup is being pissing me off for the past few weeks. Too hard though :(

PoPToP probably not a bad idea, if you need a custom panel you can definitely make a post regarding it in the Employment section

poptop hasn't been updated since 2006, and when I used it at that time the reliability was pretty horrible. It doesn't have support for basic networking functionality like out-of-order packets, and causes all sorts of problems.

OpenVPN is really your best solution, but takes a lot of work to get going in the kind of service you're looking to provide.