I use the 1/32 scale wheels and tires from the New Ray models found at various truck stops, here in America....Not sure if there is a website or something that you could get them from....Those little models are pretty cool, and I hate to have to rip the wheels off of them, but you have to break some eggs to make an omelette....I know the UK has something similar to these, but as a rule of thumb, anything 1/32 scale could offer some decent sized wheels....
And thank you, very much for you uplifting comments....Coming from you, that means a lot....I've seen some of your amazing builds, too....