I can help you make a website.
I use drupal ecommerce and set it up for you. It doesn't take a long time to do for me. But if you want to do it I would get a book on it at http://www.amazon.com and then you can see if this is what you want to do. There are shopping carts you can add to it and also wordpress handles this kind of stuff.
But it will take time for someone who doesn't know anything about it to configure it and get it running not to mention all the knowledge you have to have about the internet for it to noticable on google.com and bing.com. You may want to get help.
I relatively make this kind of website for about 300.00 and configure the taxanomy in the website to keep track of orders. There are lots of other software as well like OSCommerce and that is easy to take care of and I believe you can connect it up to paypal to receive your payments. You can email me at firstname.lastname@example.org if you decide you need some help if not good luck to you and I hope I helped.
If you need somewhere to host it after you are done you may want to try http://www.powerhash.com they are a good hosting provider have had them for years and they are great.
You can also try http://www.wholesaledeals.co.uk if you are looking for wholesale deals to resell on eBay UK and Amazon UK. They basically research for you which current wholesale offers are selling successfully and at good margins on eBay and Amazon, and you can join their service to find out where you can buy those deals today.
Since you are looking for clothes
Try this page: http://www.wholesaledeals.co.uk/search-suppliers/clothes-suppliers.html
Hope this helps.