Road Angel and Origin B2 will tell you if you are exceeding the limit near camera sites, and some mobile sites. They also have laser detectors that are completely useless, telling you that you have just been done. You can also set them to beep if you go over a pre-set speed, usually 70. They are a help but not a complete solution.
I have driven with 9 points on my licence it is a horrible experience, every journey becomes stressful and your driving standards will plumet as you keep one eye on the speedo and another in the bushes and at the bridges looking for hidden talivans. You have it even worse than I did thanks to the recent deployment of so-called talibikes (motorbike with speed camera on) You also have over two years of it to go.
My Destinator-based satnav system has the facility to tell me if I am exceeding the speed limit for the current road, but this facility is only as good as the information stored in the maps. All it needs is a local council to lower a speed limit from, say, 40 to 30 (something they usually do by just removing the 40 signs one evening), Destinator wont know about the change until the 2007 maps come out and *ping* you have just gotten yourself banned.
All I can suggest is to be very careful, keep an eye out for the signs and stick to the limits, don't rely on any gadgetry as none of them will work 100% of the time, and please, TRY to keep an eye out for pedestrians, cyclists, bikers and other cars etc as well. I know it will be bloody hard work, but if you hit somebody by hitting them at 29.97mph with no attempt to stop, they will probably end up dead and "causing death by careless driving" is likely worth a longer ban than just getting banned under totting up.
Do you need to drive for your job. Is it possible to take any alternative forms of transport such as bus or bicycle? I would try to minimise my driving, thus reducing my exposure to risk and reducing the risk of me injuring someone else.
Good luck whatever you decide to do. You have my sympathies.