Try this : Vinyl Depot !

If you are unable to find the right size, here are a few options to consider:

1. Could the opening be reduced by adding small sections of fencing on each side?

2. Could the opening be expanded to accommodate a slightly larger gate?

3. Is it financially feasible to have a gate custom built to fit this spot?

Just doing a quick internet search, it looks like there are a number of fencing vendors in your area that could assist in finding a solution. Good luck!

Best will be to have it Custom built to fit.

Ensure the Contractor use Aluminium in rails and uprights so hinges & latches do not tear out of the PVC /Vinyl gate

I am sure Illusions Vinyl can assist in your area.