One of my Requirement is that i need a sandbox with unlimited space for Knowledge Articles. Can i get this in Partial Data Sandbox or in Full copy Sandbox ( But in Full Copy Sandbox i do not need Production Data only Configuration Data should copy).
You'll never have unlimited space for Knowledge Articles - each article will consume 2Kb of your record storage limit so you will eventually run out of space.
All sandboxes will copy over configuration - the partial and full copy will also take some or all of your Salesforce data, which will consume a chunk of your record storage.
A developer pro (the new name for the old config only sandbox) now comes with 1Gb of storage, which is enough for over 500,000 knowledge articles.
A partial sandbox comes with 5Gb, so enough for over 2.5 million articles, but you'll need to specify a sandbox template and copy some data over as well, which you will then have to delete to free up the data. You should be able to reduce the amount of data by choosing a very restrictive set of objects in your sandbox template - you may even be able to specify no data, but that's not something I've tried myself so I can't say for sure that it would work.
A full copy sandbox will come with as much storage as you have in production, but will also copy most of your production data over which you will again have to delete.
You haven't provided the details as to why you need 'unlimited space' but you might be just fine with a developer sandbox.
We have a custom import process in our org that imports thousands (near 10k) of articles into Salesforce and also makes thousands of updates (new article versions and translations) , we often make test imports and updates in a developer sandbox and so far we have not reached any data storage limits. If you will be using that sandbox just for knowledge articles I don't think you will have to worry about this.