The Documents module is open source https://github.com/DNNCommunity/DNN.Documents I personally do not use it but I have worked on that codebase in the past to make it work past DNN 9.2.0, I'd be happy to take a look at making it work in DNN 10 if you are willing to sponsor some of that work, see https://github.com/sponsors/valadas

Feedback is also open source at https://github.com/DNNCommunity/DNN.Feedback I have it working on a DNN 10.1.2 production site but I can't submit on that site and don't have it on a local instance to run extra testing, what issues are you experiencing with it?

Ultra Media Gallery and Ultra Video Gallery: unfortunately those were commercial modules and the business no longer exists. I would recommend migrating to other solutions. Depending on the complexity of your needs, there are other commercial modules (which I don't really have specific suggestions for) or many people just now handle galleries using structured content like 2sxc, they even have a fancybox app you can just use out-of-the-box https://2sxc.org/en/apps/...d-for-dnn-and-oqtane I am not sure it supports video, but it would probably not be to hard to modify it so it does (I guess). There might be others have more suggestions as I don't do a lot of galleries and when I do, I usually do my own very simple thing in 2sxc.

Canam Wiki: I had to google that one, never heard of it. We have a Wiki module that is open source https://github.com/DNNCommunity/DNN.Wiki It is also one I don't use but thanks to a generous (and anonymous) sponsorship, it was just updated recently to work in DNN10. I don't know how it compares to yours, but is is free and open source, so it can be improved potentially if it does not have feature parity and/or it is a huge pull to migrate and you would want to sponsor some sort of import feature...

> Our goal is to replace these legacy components with supported, future-proof solutions while minimizing rework and technical debt.
It is hard to predict the future. Commercial modules are often more feature-rich and modern but there is always the risk of the company just disappearing. There are some vendors that are more known than others in the DNN world. I don't want to start listing them as I'll forget some important ones and get flamed. But the DNN store has a Top Vendors page https://store.dnnsoftware.com/top-vendors where you can familiarize with some vendors that have more than a single module and might have more chances of disappearing that vendors that focus on DNN solutions (and have an extensions portfolio).

Open source solutions have less chances of just going out suddenly but are often (not always) a bit older and less maintained unless if developers use them or deeply care about them or get some sort of financial support to keep them updated.

We have a free Open Content Template for Images, originally built to replace Ventrian gallery: https://github.com/40fing.../04.00-Image-Gallery

On this site there's (basic) video gallery, also in Open Content. Might not cover what you need, bit still. https://dnncommunity.org/Docs-Learning/Videos

Whether those are useful depends a bit on the module you used before and what options it had. But essentially anything can be added to the functionality of the Template.
I would definitely advise you to start using Open Content or 2sic as that's the most future proof solution IMO.
But if you don't have the knowledge to build a template you would need someone that does that for you.

We're moving to 10 shortly. We maintly use Mandeeps modules, but also the gallery module from EasyDNN Solutions. The say it's 10 compatible, and it handles images and videos very well. It's a good outfit, in our experience.  

We use Revindex Wiki, which is also 10 compatible. It's simple but very nice. 

John

We use opensource suite of modules for all of this kind of need. : https://www.rocket-cds.org/
Specific needs can be adapted with AppTheme design in razor or bespoke plugins.

Sandun, I suggest you see Mitchel's post about the Documents module in this thread: 
https://dnncommunity.org/...nd-documents-module/

John

For a premium state-of-the-art offering also check out Plant an App www.plantanapp.com.
It's DNN 10 compatible and comes with features from form building to workflows, search engine, automation, API builder and a lot more.
It's also exceptionally well supported, from small to large organizations with complex compliance requirements.