My first ZT was a ZT0350.
It is on the heavy side but I can only recommand it to "get i touch" with ZT.
IMHO the ZT0350 emphasis a lot of the original philosophy of ZT... durable, heavy folding blades... "built as a tank" and "proudly overbuilt in the USA"...
Nowaday they offr a lot of more different designs, some beeing almost gentlemen folderS.
They are great knives, but for me they are not really in line with the "concept" of ZT.
So to start with ZT, I think a ZT0350 or a ZT0566 are good entry level knives.
In the 150$ range with good steels, assited opening, etc...
Notes that they works fine deasisted, so shall you get tired of the assisted opening you may be able to remove the torsion bar easily.
again recently the 0562 and 0801 have been released with KVT ball bearing, premium steels and materials, and a price just above 200$.
You can also look at the 0450Cf if you look for a gentleman folder is great.
I didn't try the emerson by ZT but I have read good comments on them.
However they are too tactical for my usage, but it may fits you also.