Well done ... while not being entirely unique, your cab looks good !!

You've stayed within your budget, and assembled a pretty versatile cab. Mission accomplished (well, phase I, at least).
Not everyone has the skill, combined with the time, to invest in making their own cab from scratch. So don't worry about your reliance on vendor supplied components.
The X-Arcade XXL is vastly more customisable than other models such as the TankStick and Dual (Two Player). It is larger in all dimensions, width, length, and height (depth), plus it has a sturdy, solid design that is twice the weight of the TankStick.
You've got plenty of room on either side of the XXL to mount a spinner, maybe a good addition would be to whack a TT2 onto it.
Another idea would be to change the sticks at some stage ... plenty of different choices in that regard ... that panel should even have the depth to mount rotary sticks, if they're to your liking.