Hi Nick,
I'm a bit of a closet Scalextric buff and have a a good couple of hundred yards of track and about 150 cars at the last count. With regards to powerbases you have to be a little careful, what you want is most likely an old classic powerbase that works with all hand controllers. The powerbases you describe on ebay are scalextric sport (not digital, sport) and your classic controllers won't work with these you would need to buy two sport controllers as well. Like the people say you can buy convertor track to then hook the sport powerbase into your classic track setup.
Now digital that is a whole different kettle of fish. Digital handcontrollers won't work with classic or sport powerbases they need the digital powerbase, of which there are two types, one will allow 4 cars to run simultaneosly, the other will allow upto six to run on the two lanes. Digital cars will work on classic and sports track, but non-digital cars will not run on a digital setup unless you have soldered the relevant convertor chip between the pick-ups and the motor, you also need to cut a hole in your car to allow the lane change sensor to see the track.
I was looking into the cost of converting my set-up to digital and the lane change and powerbase is not overly expensive, but the cost to convert the 50 cars that I run on a regular basis was going to work out a more than £500. Each saloon/sports car convertor chip cost £11 to buy, I am planning to write to Hornby and see if they can do me a deal on a bulk load. Either that or I will join a club once I have moved and see if I can wangle a discount through them.
Its a pity all my stuff is in storage at my mums or I would have just sent you a new one in the post I have about 20 of the things I have picked up at carboots, you have to buy the sets to get the cars for spares or whatever. If you are still looking for one in a few months when I get all the stuff back after the house move you can have one.
