Well...
I have BOTH: An AT Pro (for 3 years) and an AT Gold (Brand new - 1 week).
So far I like them both.....ALOT!!!
Based on the areas that you said you would be hunting, I would recommend the......
AT Pro used in the Pro modes.
No matter which you get, get BOTH the 8.5 x 11 and the 5 x 8 DD Heads.
I recommended the AT Pro mostly because of the ability to vary the discrimination notch by notch if necessary
and the fact it is pretty evenly matched to the Gold.
So far, I like the AT Pros tone patterns a hair better. Just a little more pleasant and crisper.
The AT Golds are just a bit 'scratchier', if that's even a word...he-he.
Here is a break down on the units I would recommend based on the areas you indicated above;
jewelry - AT Pro or AT Gold
parks - AT Pro (trashy)
homes - AT Pro (trashy)
curbs - AT Pro (trashy)
woods - AT Gold or AT Pro
water - fresh: AT Pro or AT Gold
water - salt: AT Pro
The AT Gold is tuned a hair more for hunting the gold. Partly because of its 5 x 8 DD coil and the 18kHz operating frequency.
But, from the little bit of testing I have done with the couple test rings and a couple dozen various coins I have,
the AT Pro and the AT Gold seem to be pretty evenly matched when using the same size and type of heads.
Sure it has the 'All Metal' mode, but in trashy areas I don't see that as much of a benefit.
also note, the notch patterns on its 3 modes are fixed. You can not adjust them. You CAN adjust the Iron discrimination for the 3 modes though.
Unfortunately, I cannot comment as to how well either of them work as far as gold chains go. I have not found any and do not have any to test with yet.
I have the Grey Ghost Amphibian Head phones and to me, they sounds as good as the Garrett Land Head phones that comes with both the units.
I can not say how they sound compared to the Grey Ghost Land Head phones, since I have never used the Land phones.
Either will work for what you want, bit I'd lean slightly towards the AT Pro at this time. That may change as I get more time on my AT Gold, we'll see.