When I first started out I made some very bad purchasing decisions. Mostly I was trying to get what I thought I needed to fast or not having enough money to buy the correct tool.
What I ended up with was equipment that was to small, a gas GMC dump truck was one of those bad decisions and a couple of times the wrong trailers. Bought a tractor once that I though had some life left in it and was wrong. That was just one $8000 mistake.
If I had to it over again I would think very hard about what you need, have to have.
In your situation think about what you have to have to be able to do your sand bags. Other than that don't buy, make some money, and make sure this thing will work out.
How many sand bags have you sold? Don't spend money on truck bling or even lettering etc, get the most important stuff first. Once you get you first big order then think about spending money on selling more bags, not more equipment.