From everything I've read here over the past decade regarding that model PT, tire chains would most likely resolve any issues with traction on the wet slopes you describe. They are not that steep. I have to wonder if you need a machine of that size, though. Its more of a loader. A 1430 is more of a groundskeeper being smaller, lower, etc...
I would suggest you analyze your needs, like lift capacity, lift height, mowing duties, etc... very carefully before deciding on a more loader oriented machine.
How large is your orchard?