The Para in 40S&W is not the greatest choice unless you handload, as the cartidge is rather too short to be reliably fed in a 45-size frame. It can be done (wide hollow points, long loaded-round-length), but don't expect just any ammo to be reliable.
I concur that the Gold Cup should be able to shoot more accurately than an out-of-the-box Para. I suspect that your experience is either something ergonomic (grip size, trigger weight), novelty value (i.e. not flinching before the shot) or ammo compatibility. It could also be that there is something not right with the Gold Cup.
Rather than buy a new gun, I'd invest in a match barrel (BarSto or similar) fitted by a competent and experienced IPSC pistolsmith. While he's at it, get him to give the rest of the gun a once-over for any other sources of inaccuracy (loose parts etc.). Lastly, get him to install a set of match-grade fire-control parts (light trigger, match hammer and sear)... a sub 2lb trigger is possible if you just want a target gun.
Lastly, you don't say how old you are. Dare I say it, your eyesight may not be what it once was. If the Para has bright sights (dots, fiber optic insert, tritium etc), then maybe your eyes pick them up better than the black-on-black sights of the Gold Cup.
If you still want a new gun, I'd go SVI or STI rather than Para... better made and optimized for 40S&W, IMO. More expensive, but worth the extra.