Your choice of second plane depends a lot on your budget and the size of your flying area. Bigger flies better. A .40 or .60 size Big Stick/Ugly Stick is ridiculously easy to fly, but it does require more runway area and a bigger overall flying area than your little park flyer plane does. So if you have 300-400 feet of mowed grass and can afford the larger plane, go for it. Put big wheels on it so the bumps don't bother it much, and have a blast.

As for electric vs. glow, the answer there again depends. After you figure in batteries, electric will add about $200 to your initial cost of the plane in the sizes we're talking about and you'll also need a lipo charger. Electric is clean, low maintenance, and reliable. But you will need a way to charge batteries at your flying area if you want to fly more times than the number of batteries you buy. Glow power is cheaper initially and can be run as long as you have fuel. But you know from cars that glow engines must be tuned and they tend to get gummy and unreliable if they aren't run regularly. I think glow is the most practical choice in this size of plane due to the initial cost savings and the ability to fly a lot without charging batteries. And, of course, there is the third option of the new small gasoline engines. They cost more, but use the same fuel as your weedeater. They are the most practical power system of all IMO, but they do cost more than glow engines.