If you're only going to do trails, then something like the Maruader would be good...but you still have balance issue. The KoolKat would be very easy to build (compared to the Maruader). It's best to select a design that you will follow thru to completion and enjoy, rather than spend alot of time and get frustrated and stop the build before you even get a chance to ride it. And the KoolKat has a much higher seat, so it will help with balance issues, even though you may feel uneasy with the high seat/pedals at first.
Another option would be a Toureasy clone, which many people have built and enjoy.