I am considering buying a Reo Grand and I have a question regarding the bottle. My current setup is a Silver Bullet and J-Tank. I have a few J-tanks, as I like to be able to switch flavors during the day. It is easier for me to just have a few tanks than go through the hassle of changing the liquid in 1 single tank. With the extra bottles that you can order on the site, are the caps solid or do they have a hole in the top like the 1 that comes with it to fit the tube inside? I want to get a few extra bottles so I can fill them with my favorite liquids and be able to change out the bottles during the day AND be able to transport the bottles when I am at work. I travel a lot and often have to carry extra tanks and liquid with me. I'd like to do the same with the Reo Grand.