I bought my Led's from eBay with good results. I've done the replacement on both TT's we've owned. For the 921 bulbs I've used the flat card style of replacement and I look for a color temp of about 3000K and an output of about 180 Lumen. I give a miss to products that only use adjectives to describe the product (warm white, bright.....).
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks