Don't let the fact that the Ebay LEDs are shipped from HK bother you. I have ordered several times thru him and always recieved my orders in 10-11 days after payment is recieved (via PayPal).
Also, most places are going to charge you $4-6 for S&H; the Ebay store offers FREE shipping! Buy it Now for 100 red 5000mcd LEDs is $21 and includes 100 resistors for 12V operation (which you won't need if you are grouping your LEDs).
I prefer this myself over the bother of group buys and extra S&H charges, and at $.21 ea. it sure beats RS!!!!
and yes Motor City.. I agree..
always check the specifications of the leds you are using prior to wiring and selecting a resistor.