As someone in their late 30's and now coming up for 40's who has a genuine medical condition or disability and who has to deal with incontenance (see my earlier posts),
I would say, start by getting some free samples this can be done online or by finding and contacting a supplier by telephone.
Then if you can get the ones that you want you will need to find out how much they cost and then make a decission on when to get them.
I personally usually don't buy less than a pack of 10-20 adult sized disposable diapers from a good retail shop although this is not exactly small buying in quantity and, as this post is referring to small quantities I would probebly say find shop online.
Or a pharmacy/medical shop where you can buy them if you have a perscription or just tell them you have a problem with incontinence and see what they recomend of cause this might include a medical consultation but if your ok with that then there shoulden't be a problem.
Or the other option is to simply ask if they have any broken or opened but un-used packs of adult or child sized diapers they cant sell as these should be avaible for a discounted price who knows if your lucky enough you might even get them for free.
Other than this I would recomend sites like Tena, bambino, nappiesrus, drydayz or other retailers like dry/247 and others that I can't think of right now off the top of my head.
Anyway look for ones that have a large absorbancy and are comfortable for you to wear you don't want any accidents or to feel anymore un-comfortable than you otherwhise need to be my advice is don't go for cheap ones that will look rubbish as they usually are the worst ones instead, and if buying online go for a brand you know or trust.
If your buing from a pharmacy or shop go for what they recomend, it might cost more but at least you will feel more comfortable in the long run.
But as every country is different I would say look at what's available in your area and go from there.
Hope that this helps and that your staying comfortable and dry and safe as ever.
yours sincerly
Chinababy888.