Looking to put together a full hydraulic steering system. Rams helm and pressure tank. Single trs drive boat. Can I use any rams with the air tank? Or have to be hynautic? What helm should I look for? Like to not be 10 turns lock too lock. Any input appreciated and if anyone has any parts kicking around lmk.
thank you!

Check out this catalog. Lots of good info including lock-to-lock charts for different helms vs cylinder combos.
https://www.imcomarine.com/nvcatalog/imco_catalog.pdf

Having gone down this road already, you'll be miles ahead if you can find a complete set-up being replaced. Lots of misc parts add up if you have to piece them all together. I got my system from a member that was adding extension boxes and wanted all new stuff. Check out the swap shop.

Can I run H21 helm and hynautic pressure tank with these? I think they’re old lathams

Is this for manual hyd steering or will you be using the power steering pump?
Sounds like a manual hyd sys. If so, I have no experience with that.

Yea manual want to lose power steering pump. Do the hynautic pressure tank and helm

It'll be easier to keep the power steering pump especially with the weight of the TRS drive.

If you haven't purchased anything yet, reach out to Sick Stinger (Mike Mello). He'll probably have everything you need at am really good price point (used take-outs).