You have an interesting dilemma. I seldom post on this forum, but I thought your situation was interesting.
I've had a fixed location for over five years, and I have never been mobile, nor would I, in my area.
Noting that I have a definite 'prejudice' towards being fixed, I offer some advice.
A well designed, professional appearance in your Shop gives you instant credibility. Use your truck as a billboard, and park it in at least one adjacent, conspicuous location.
A Shop allows you to work, regardless of the weather. You will be more efficient since you'll eliminate travel. A Shop allows for heavy-duty equipment - a quality extractor requires 40 amps! A steamer requires its own 15 amp circuit, and on and on. T o sum up my admittedly one-sided opinion, I simply could not do 'my level' of work on a mobile basis...
Look in to spending a week or so in an established, volume, upscale shop. That offers invaluable insight and experience. Also, most chemical suppliers offer some training (some much better than others) which can offer insight into selecting the proper chemical for the task at hand.
LOCATION, LOCATION, LOCATION. It doesn't need to be on a main thoroughfare (but maybe your 'billboard' could be....

) , although it needs to close and convenient to the upscale neighborhood(s) that you'll be targeting. Do a search for demographic data on your area. Where is the population with the highest average household income? Highest mean home values? A commercial real estate agent can be very helpful in this area - find one.
Hope this helps. Best of Luck!
JB