Places like Transair and AFE do "packs" which, I believe work out cheaper than buying the individual items one by one but they are usually a fair amount to stump up for in one go - I think about £200.
Your instructor will be able to advise on what you need and what will best suit.
Also bear in mind that some items are more expensive in the pilot/aviation shops and catalogues and with a bit of lateral thinking, you could source the items much cheaper. To that end, I am thinking of hi-vis vests (I've never paid for one - I seem to acquire them) and stopwatches (go to a sports shop). If you want gloves, go to a golf shop and chinagraph pencils and map pens are much cheaper from a stationers.
Cheers
Whirls