I bought the PS2 kit through MTHRRC several years ago, probably about 2006. I recently replaced the battery with a Digikey supercap. The PS2 kits are no longer available, but MTHRRC is taking orders for the PS3 kit, to be delivered in a month or more. They are accepting orders at $149. If you are not a MTHRRC member, you can get a basic (no car) membership for $25, which is less than the extra price for a kit if you're not a member. I just ordered 2 by phone.
I'm actually considering selling the Shark with a set of 5 B&O streamliners, which have LED lighting.