Hi, I'm going to be taking a long haul flight in a couple of months and want to make sure I've got good isolation on my chosen IEM. At the moment I'm using UM2 and IE6 with stock tips, and getting a CK10 in the post in the next few weeks. For the best isolation, should I buy an er6i? I'm reluctant to do that since the sound signature will be similar to the CK10 that's in the post. I'd rather buy some new tips. What do you recommend? Buying new tips (if so, which ones?), or going the whole hog and buying the damn ety.