Joe has some very good advice about the type of flying you'll be doing.
To kind of restate what Joe said, there's three basic sizes you can get for a L1 cert.
- Small - will fly on E or F - H, where and H will really get it some altitude.
- Medium - will fly on G - I motors where an H will get it up there, but not too high.
- Large - will fly on H - J or K motors where an H will keep the flight low and slow.
I like the Binder Design kits. I have a Thug and it's the rocket I fly the most. I have the 29mm version, but I would recommend the 38mm version just for the larger selections of motors.
If you are looking for a Small kit,the BD Thug is a great one.
In a Medium, the Excel & Excel Plus are excellent, as is the Iris
In a Large size, there is the JackHammer, Sentinal, Stealth, and Samurai.
The California Kid is a Large kit that is a little more advanced but is pretty cool and recommended for H - K.
The Binder Design kits do not come with pre-slotted tubes. You do get to do some building instead of just assembly. The instructions are excellent so don't let that deter you.
Good Luck. I'll expect to see a build thread and flight report,
with pictures!