If you want my honest opinion, No a 3/4 ton isn't enough to drag that much water around plus equipment. The trailer is rated for 7000 lbs and the water alone takes that up. If you are talking about a 20 foot trailer, it's 2500 lbs by itself without anything in it. That leaves you with 4500 lbs payload. Add the machine and propane tank, hoses, hose reels, chemicals, brushes, and all the other crap peoplel put in these things, and you are toting around more than what's legal without a commercial drivers license and more than likely you are surpassed the gvwr of the 3/4 ton truck.
I've had both the Ford and the Dodge and the Ford is less expensive on maintenance. I do like the cummins though. It has a lot of untapped horse power and can be stepped up quite a bit.
I currently have a 1 ton ford box van with 2 machines and 300 gallons of water and that's a lot of weight. I have to get springs for it to handle the weight.
If you want a little help sometime in setting you trailer up, just let me know. You can always email me too.