Brad,
Congratulations on your soloing!
A second airplane and your asking us?

There will be a great many suggestions forth coming as there are a great number of choices. OK here's my suggestion. First of all stick with your trainer for awhile there is still a great deal to be learned by flying it. Don't be put off by the trainer thing, I instruct at two clubs still have a couple of trainers in my hanger if that tells you anything. Trainers are good birds for relaxed days of flying and practicing touch and goes, a good fall back airplane.
If you want to build a kit something like an Ultra Sport or a Ugly Stick setup with tricycle gear might be a good choice. Stay away from a war birds for a while or really go fast airplanes until you get some more experience under your belt. An Easy Sport would be a good ARF selection on a second bird while your building your kit.
Blue Skies and soft landings