Are the pictures an accurate refelection of the product
“Most office chairs have the 5 wheels on a 24 inch or close diameter. Some are with a 27 inch diameter. If you are very heavy, tall maybe or have experienced chair fails, a heavy duty oversized ie 27 inch diameter chair is a good idea. If you are very heavy or you need a chair say in a 24/7 control room or call centre as in an emergency role offering three or four shifts in any day then there are specialist office style chairs . Specialist chairs I have seen can have twice as many "legs/wheels" and will obviously be highly adjustable but no doubt very expensive. A good compromise might be as I did is to find a chair base like this one you have an adequate chair. The word ergonomic might help you find what you are looking for.
I have bought Chinese knock off chairs and been pleased with the result. Shouikld you try and improve on a vinyl covering using a local jupholsterer you will find out that bespoke costs many times more than some Chinese super factory or sweatshop, you will never know unless you personally investigate.
My usual source for home role chairs is charity shops or the local recycling centre. But where safety might be an issue or responsibility for others, then it should be new every time. If you do not know if a chair might have been abused..even in a retail setting, new is safest. Just think of the hours you are
going to spend. When researching one £10 tip find the comments I have seen about the common IKEA Markus chair that can wobble makes an expensive chair supposedly from a design leading provider possibly in that regard a false economy. One happy find is that most components are standard, yet withion the office chair category some are plainly lightweights, and you probably get what you pay for.
Lakeland Furniture have a good range, and I found my way to them appropriately easily.”