If finance is an issue,as surely it is for most these days, then utilising what you have has to be the clear starting point. Fortunately, you already possess an ideal sidecar hauler in the Gold Wing. At the risk of offending solo Wing nuts, I still reckon Honda actually designed their grand tourer for sidecars, but simply didn't mention it in the press release.
From the outset, with the GL1000, enthusiasts all over the planet saw this as their ideal motorcycle. Initial problems with the clutch raised doubts, but these issues were dealt with by improved designs. Increases in capacity improved the attraction, as did the increase from 4 to 6 cylinders.
Obviously, there are things to be dealt with when it comes to creating the whole rig, but the pairing of the big Honda to a suitable sidecar is well established, so there should be no mysteries. I'm sure you won't regret it.