I took my PSR-500 to Barber last weekend for the IndyCar race. It was really overkill for the race, but I already had it and I could use the signal stalker feature to find new frequencies. I also made use of the PL/DPL search feature to ID the tones that the drivers were using on their frequencies.
I've also been looking for a smaller, cheaper scanner, but so far I haven't found one that gives me the PL/DPL search and store feature that works like my PSR-500. Besides that feature, my other requirements are a alpha display, computer programming and a signal stalker/close call type feature.
I also purchased a Pole Position audio booster from Racing Electronics at the track last Sunday. All I can say is WOW! It really makes a difference. I only had to turn up my scanner to the minimal volume setting. You get a free 2 or 3 way splitter with its purchase. My headphones are Koss QZ-99 models. I also used an old UHF Centurion commercial 1/4 wave rubber duck antenna and I had minimal interference problems.
Whatever scanner you purchase, I would recommend that you program in the frequencies well in advance without tones. That way, if the tones changed, you won't be out of luck. If you PM me your email address, i'll be happy to send you the list of frequencies and their tones that the drivers were using at Barber.
One of these days, i'll make it to Indy......