I agree with Mike on the LTD company thing. We are a LTD company and there is still an advantage for us (my wife an I). The advantage becomes less and less every year though. There is really only an advantage if you have two directors from the same household running the company otherwise its just extra work, expense and added complications.
I have run a machine with similar specs to a storm from the van for many years now and imo its the way to go. Most jobs are within 75ft of the van and as the more powerful machines can run up to or over 150ft of hose its more than possible. Is worth having a smaller machine for jobs in flats, etc .. though.
One thing initially is to get on some form of training course, some machine manufactures offer them as part of the machine sale. A course sets you up and gives you some solid information to start with. The quality of facebook and forum gleaned information can vary alot.
Marketing is really important to start with. As people are at home more now leaflets is a good place to start. You will need lots though, like 20000. Cover an area then aim to cover it again within one month if possible. Be picky about the houses you market to, it will determine the type of work and the amount of money you can earn. Local mags, websites, facebook page, and targeted letters are all useful, if not essential. The main thing is do a good job, be punctual, respectful and smart and you will get repeats and referrals.