I have a Minisup and a ED Lovelydoll. Usually their wig size is 6-7. I am going to purchase one of the Dollga Heat resistance wigs, but on Leekeworld's web site their sizes are 6-6.5 and 7-8. Which size should I get? I'm just a wee bit worried that I'll buy one too small. I have heard their sizes are on the small size?