Help with graph questions please?!

Ok, have to admit I have no idea about graphs, what's compatible, what's cheap, what works good, etc etc...
That being said, I have a gen1 10" with ds/si at the wheel and a 5" at the bow. I'm wanting to upgrade with another 10+" at the wheel and a 7" at the bow. I want them to be linked together. I want to be able to use ds/si at both. All that being said, I don't want to break the bank. Thanks for any help, I really don't know this stuff to well.

Do you want to share a single DI/SI transducer or do you want one on the trolling motor and one on the transom?

Defiantly like one on troller "have the troller with one built in" and of course the transom

Nobody makes a SI/DI transducer built into a trolling motor, those are all 2d sonar (regular sonar).

See, told you I didn't know lol.

So, how does it show di? Is it linked to the transom ducer?

If it is showing di now and you don't have an external transducer attached to the tm, then yes it is sharing the transom transducer.

Any input on what brands?

You need to go somewhere that sells graphs and learn the basics or maybe watch some YouTube videos. It would take too long to try to explain all the options if you don't know the basics yet.

Depends on your opinion of cheap. To me there isn't a cheap 10". The 7", something like the Helix is cheap but you have to go up to the 9" in it to link them. I think the size of the console unit and the linkable feature is going to be what gets your price up there. You might find a humminbird 899 on sale because they are being discontinued. You can link it.