I think you're heading in the absolute wrong direction.
You need to determine a couple things before you do what you're doing on the financial analysis side.
The first thing you need to do, is figure what kind of business you're doing---that alone will dictate your equipment, and thus your cost. Are you only mowing or when the next shiny truck pulls by are you gonna decide you want to start mulch, snow removal, whatever. Without this understanding (at least a starting point--called a business plan) just go to Burger King and ask for the paper hat job. You WILL buy the wrong equipment unless you do the best you can to determine your needs.
The second problem is that the mentality of I need a huge truck, and all new stuff will put you in the poorhouse quicker than a cat can climb a tree. Without business (read customers) you're gonna need marketing and lots of it. Word of mouth is best but you need to get your name out there......you're not going to get any business by just riding around with your new truck hoping someone flags you down.
These guys are all right---buy what you need, learn to budget your earnings and the true cost of your business will fall out. Remember one thing if nothing else..... you can't plan for everything and its you're fallback that will eventually save your azz.
Buy an older decent used truck....but first, figure out how far you're driving. You don't get paid to ride around. Forget the F350 and forget the diesel. You don't need a big block to tow a 6 x 12' trailer, and its a waste of money. Just get something w/decent paint so you don't look like sanford and son.
Get the best commercial equipment you can--new or used. Dont go buying a 60" mower if the only customers you have are on 2000 ft lots. Good used commercial equipment will save you a ton and work well for a long time w/ decent maintenance. Look in the want ads for some stuff---theres a million guys who thought they knew last year and realize they didnt this year. There are REALLY good deals this time of year in the used market...most stuff barely used. You just have to beat the rest of the lawnsite members to it! Good luck, they're fast!
Because you're new, reserve some mentality and financial support for growth into other areas (if you plan on more than mowing). THIS IS DIRECTLY RELATED TO YOUR BUSINESS PLAN! In short, you aren't loading a lot of soil or pavers on a 6 x 12 open trailer....you might want a small dump someday or maybe a trenching machine if you get into irrigation. Keep an open mind here----and remember, you can't do it all right away.
And last, sorry, but your numbers are whacked. You're way too high in a lot of areas--being conservative is good, but try to hit it within 20% of actual if you can.... example... $1500 annual for a trailer....are you buying a new trailer every year????
Try to get a tight route, buy a used F150 or equiv., a decent trailer--used is OK too. Get the best mower, blower, and trimmer you can, and then figure out a good marketing campaign. And remember, some guys made out OK using only aRanger and a 21" mower. You're not Donald Trump...........yet!