You could also do with checking the steering wheel height before having it built. If you have something handy to put your monitor and wheel on, and then play with height you could save some time. As I found, I had to have the monitors quite high up to get the realistic feel in the cockpit. As a rule of thumb, your wheel needs to be between shoulder height and chest height for you, and the wheel should meet the virtual wheel on your monitors. The only time where this isn't the case, is when karting, normally in a kart the steering wheel is quite a bit lower, but still chest height.
I know it's going to bring other questions into the game too though, such as peddle positioning, should it be flat to the lowest point of the seat, or 10cm lower. Thats all up to what cars you'll be driving, formula cars are always flat to the seat, most race cars are all flat, all karts are flat, but a rare % of touring cars and a lot of pre 2000's cars are up to 10cm lower. That being said, do you then want them mounted from the bottom, or inverse?
Also, the seat positioning is crucial. All road cars re-designed for racing have a backwards lean of 10°, this allows for a shorter, shallower car, and it also makes the car easier to drive in longer races and stints. The only difference is, formula cars and prototypes have either less or more, depending on the drivers height, and weight. And then road cars, that have been trimmed for racing but not re-designed tend to have less than 10% lean (which makes it painfull to sit in after 6 hours lol).
Having a track-day in a formula car will give you a much better Idea on seat position, wheel height, angle and distance, and monitor height. There is no substitute for the real thing, so if your trying to get closer to reality, get a feel for reality first.