For 55mm hub cars, you can buy Yaris discs, I have a set of these, J hook type.
http://www.mtecbrakes.com/brake-discs/toyota/yaris-06-12/yaris-1-33-vvt-i-01-09-03-12/front-brake-discs/mtec1610.html
My setup is the 275x22 kit
As for pads, you're looking for pads that fit a Wilwood Dynalite caliper, for example, the part number for EBC Yellows is DP4001R: http://www.ebcbrakeshop.co.uk/wilwood--dynalite-cotter-pin-use-7112-ebc-yellowstuff-brake-pads-dp4001r_p1157346.htm
I use Ferodo DS1.11 pads in my calipers, I buy them from Circuit Supplies, I can't remember the exact code for the pads, I do have a box at my unit though will try and remember to make a note of the part number next time I'm there.
I'm pretty certain it's this one: http://ecat.ferodoracing.com/car-racing/brake-pads/FRP502
Looks like you can get DS2500 and DS3000 as well.
When I got my kit I was very keen to be able to buy parts for it away from WMS, just in case they disappeared, I'm glad I did.