This is the source for these items in UK - Link hidden: Login to view
Although the site does appear to sell retail since there isn't any link showing their wholesale program, they responded to my email regarding your need and I am copy pasting their reply:
We supply many retailers on a wholesale basis. Please can you give some more information - Do you sell online (what is your website)? Where are you based? What quantity of jumpers are you looking to order?
Alternatively we offer an affilliate scheme for resellers, the details can be found at:
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There's another one I'm looking at with products having resemblance to most of the pictures you have attached. I also sent them an inquiry on your behalf and I am still waiting for their response - Link hidden: Login to view
I tried looking further and realized that bulk of the possible sources are from China. I then spent time trying to see one that will be a good supplier for you but I wasn't satisfied, now we're back to the UK based suppliers, which I think is a better solution. :)
Let me know if there is any message you need me to relay to Link hidden: Login to view (You may directly communicate with them at email@example.com)
and also let me know if there is anything else I can do to help. :)
All the best!
P.S. Please note that we cannot guarantee the safety of any suppliers outside SaleHoo.