1: Fastgun turnbuckles and locks.
There are less expensive tie downs, and I question the need for locks unless you go with the Fastguns. The locks are to prevent a thief from stealing the Fastguns, not the TC. If they wanted the TC, they would steal the entire truck and TC. 2: Added leafs in the front of the pickup.
It is very rare to need leaf springs in the front of the truck. The rear possibly. There are other options other than adding leafs to existing springs. It would behove you to do a lot of research before spending money on this modification.3: Airbags.
Airbags are my personal preference. More often than not, adding springs is not necessary and you will have a much softer ride with the TC is not loaded. Although the added springs will reduce the amount your truck will squat in the rear, the air bags will bring it back to the original height. The added bonus is the ability to level the TC with the airbags while camping.
My suggestion is to drive the truck loaded with the TC, before making any changes in the suspension. See what you do not like in it's handling, and correct from there. Each of us have different preferences and expectations in how our trucks drive.4: Mounts added for the turnbuckles.
There are several options with this one. I suggest you use the search feature and read what others have and why. Actually, I suggest using the search for all of your questions. This will allow you to ask your questions more efficiently. 5: A Honda eu2000is Companion (which should be able to completely power the vehicle with a 11k BTU A/C.)
I am not sure why you would need a Honda eu2000is Companion, unless you are going to run two Hondas. I do not think you will need two Hondas to run your 11k BTU A/C. I have a Honda eu2000is which runs my 9200 BTU A/C just fine. I would certainly try one Honda before buying the second one. 6: Solar panel + MPPT controller.
This can really contribute to positive camping experiences. There are many choices in size and components.My personal experience and preference is to start with a smart 3-stage charger. A good source and a wealth of info is BestConverter. You should also review the Tech Issues Forum on RV.NET. You will find a lot of information there an chargers and solar related stuff. Although not one of the solar components, it is almost a must when plugged into shore power or your Honda.
For the solar, 130 watts is a very good start, with a controller big enough for you to add panels in the future, if you choose to do so. Due to the limited space on the top of a TC, consider a couple of small panels to fit. I choose two 65 watt panels, one on each side of my cabover vent. Although I can tilt my panels, I have never needed to do so. With the 130 watts, the only time I run my Honda is to use the Microwave or Solar. I did install all L.E.D. lights.
If you can initially afford only the solar or Honda, go with the Honda. It is much more usable than solar, requires no sun and puts out more usable energy.
If your truck does not have a rear sway bar, I suggest you put that at the very top of your list, before any other suspension mod. The shocks are not nearly as important, and personally I would put them at the bottom of the suspension mod list.
I would absolutely put tires as the first thing to do on the truck. People are stuck on using the Load Range (letter) in discussing tires. I suggest you use Load Capacity (in pounds). The objective is to insure your tires Load Capacity will be adequate for the weight of your truck and camper. The stiffer the sidewalls of the tire, the less sway you will experience. The greater to Load Capacity of the tire, the less sway you will have.
Wayne