Welcome to the Dark Side!
I don't have an opinion on the HK J-3 Cub, but someday I'm sure I'll build it. In the meantime, my opinion on a first balsa build is different than Foam Addict's, in that I don't recommend building from scratch for your first build (or even second build for that matter). Instead, my recommendation is to spend a little more and get a proven kit which has been around for a while, that many many people have completed and flown successfully. With any of the HK kits you often are left out on an island with little support. The instructions are horrible at best. The quality of the balsa and laser cutting is suspect. And the flight characteristics are questionable.
But the kits are cheap, so it's easy to get duped into buying one.
Then you spend more time and effort trying to figure out how to build it because of the lack of instructions, you end up buying parts you didn't know you'd need. You spend extra time sanding and test-fitting and living with sloppy part fit because the cutting wasn't done well.
Instead, I say spend a couple bucks more and get a good kit from a trusted manufacturer, one that you can get help with as needed. There are a lot of them to choose from, such as Mountain Models (one of my favorite companies - check out their Switchback or Dandy kits). You'll pay more - their kits start around $50 or so, but what you get is worth it for a first build.
As an example, I recently built the Mountain Models Dandy for my dad. It was a very easy build which took me about 3 days total. Most of that time was waiting for glue to dry since I don't use CA glue. The kit came with a 9 page instruction manual, full 8-1/2" x 11" paper printed on both sides with ENGLISH text and tons of pictures. Pushrods, velcro, wheels, landing gear wire, etc were all included. I needed to supply the covering, covering iron, pushrod ends, and electronics. The crazy thing with that kit is that I didn't have to sand anything until I was almost ready to do the covering! The parts simply fit as they should with no extra effort from me. I've also built their Switchback and Lucky ACE kits and all were top quality kits. All perform exactly as they should and get a lot of use. The Lucky ACE has 122 flights with over 16 hours of flight time while the Switchback has 96 flights and 13 hours of flight.
By comparison, I've got 6 Hobby King balsa kits including 2 which are currently under construction. I find them a challenge due to the problems I've listed above. But I still keep building the dang things, and I don't know why! Probably because I'm CHEAP.
Three basic things to consider: 1. A good quality kit will probably be quicker to build, meaning you stand a better chance of completing it. 2. A good quality kit will look better with less work. 3. A good quality kit will require a smaller investment in tools to complete it.
