After some research, I found that diesel is my choice of fuel.
Now I need a way to pump it to the engine. My main constraint is price.
So my question is can I use a water pump like one of these, to pump the diesel?
With pumping diesel, your main constraint should be safety, not cost. There are very good reasons diesel pumps aren't for sale for $5 on amazon.
The main things you want to look at are 1) whether the wetted materials are compatible with diesel (EDPM and silicone for example will dissolve) and 2) how it is grounded. Many pumps can build up static charge which can cause the diesel to explode in the pump. You'll also need to be careful to avoid cavitation which could easily lead to explosions also.
Edit: Explosion proof motors (and intermediate ratings like totally enclosed) are also worth investigating. If your plumbing leaks, is the vapor going to find its way to the motor and explode?
I would also recommend reading more about explosion-proof pumps and reading up more generally on what types of pumps are used for diesel.