From the sounds of it you will be using your truck for your business. Here is what I would do from a business stand point.
Keep the Frontier for personal issues and write off mileage if you use it for small jobs or just driving it to the store to pick up small materials and or doing quotes on jobs.
Get yourself the F350 or larger truck and use it for business only. Keep all your tools in that truck and you will not have to load and unload all the time.
This is almost the same as my thoughts when reading through the thread.
I'd have to read more about the F350 but I imagine that it'd fit your business needs more. ie if it has a longer bed (carpet, sheet rock, etc), can haul heavier loads (tile), etc. Although it sounds like the Frontier fit your needs until recently.
Also can you write more off of it if it's claimed as a business vehicle?
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