Can the -li suffix be used with çok to indicate with lots of something?

For example:
seker-li kahve
coffee with sugar

seker-li çok kahve
lots of coffee with sugar

çok seker-li kahve
coffee with lots of sugar

Bod, all are correct. The thing is that you have too much flexibility in these situations. For instance, sentence one and three has an adjective clause wich is a noun phrase. "şekerli kahve" or "çok şekerli kahve" is a name on its own. On the other hand sentence two uses şekerli as an orinary adjective.

Notice the different usage:

I own many racing cars.
I own many cars for racing.


At the end all are correct. "Çok" can either mean "very" or "many". To prevent confusion you can use "pek çok" to make it a clear "lots of".

"çok şekerli kahve" can be two things depending on stress. "Pek çok şekerli kahve" can be only one thing no matter the stress.

It's the second one.