Yeah it has to stay plugged in. It's a new fangled kinda overflow lol. I had alot of trouble keeping siphon with the regular eshopps one so after a week I had enough and went with the one we're talking about. It's totally up to you, just sharing my troubles I had with the j tube. Most people on here most likely use the j tube configuration and have no issues. But me, nope, nothing but trouble. Plus I like not having to worry about it. lol
The skimmer, if you are gonna keep corals will be invaluable. Theres some areas you can skimp on but not a skimmer in my opinion. You have some time to save up for one too, don't feel rushed into it. You can add the skimmer at any time and it won't be a pain in the butt to do it. I just had my skimmer out while I was doing tank maintainence. hehe....