I'm not an expert when it comes to lowering the i-beam trucks, but even with camber eccentrics, it may not be alignable if it's lower than 4 inches in the front. Just be prepared for that.
Usually a flip kit in the rear with cut bumpstops will ride fine most of the time, and will only bottom out occasionally. Anything lower than just the flip will tend to bottom out more. Obviously, the lower you go, the less travel you'll have. If you're going 2 inches lower than the flip kit, then you'll be losing two inches of valuable suspension travel (hence the suggestion of a C-notch).
Speaking of the notch, a bolt-in notch should be enough for the drop you want. If you have a die-grinder, or a sawzall you should be able to do it fairly quickly and easily. You don't have to do any welding, and the cutting is minimal compared to a full custom frame notch.
None of these things are necessarily required, but they are small considerations to make that may affect your overall enjoyment of the truck once it's lowered. Having a truck that rides comfortably and doesn't destroy tires every few thousand miles is much nicer than the alternative in my opinion.
Also, it seems like your tires might be a little narrow for your wheel choices, unless you like the stretched look. (I run 245's on a 9 inch wheel, and 295s on my 10 inch wide rears and could go wider on both)