Im trying to setup a rig but have tight budget,curently have a 3100 psi 2.9 gal ,cold machine.Plan is to setup a van with its own water and machines.Woud it be better to add a hot box to my cold water unit ,or find something thats all in one used.? And when we use hot water, if the psi is just 3100 and 2.9 gal per min will that clean alot better versus cold water.? Any input will be apriciated thanks.