*UPDATED* with more buying options...
There are so many different reusable period products to choose from that you are bound to find something to suit you. From 'moon cups' to 'period pants' via 'cloth tampons' - I suggest looking at trusted eco website Babi Pur which has a beautifully curated selection of period products (although their range of sanitary towels do contain a plastic PUL layer, which means that they don't suit me).
My personal preference is to avoid plasticky ("PUL" or polyurethane laminate) layers - plastic layers cause sweating and unpleasant aromas. I've found the best pads include the following layers; cotton (against skin) + hemp / bamboo / Zorb + fleece (against pants).
I ADORE the Gryffindor sanitary pads from NanaSuesCreations (a north-east-England based Etsy shop). I fittingly met the talented Marie who designs and sews them (and passionately advocates ending period poverty) at an International Women's Day event.
Gryffindor red is the perfect colour choice for reusable sanitary protection because, well, staining is not an issue - these pads will look good-as-new for as long as they last! Now, because Marie of NanaSuesCreations is so good at what she does, sometimes there is a long wait for her products.
Izzy Wizzy Roo (from North East England) has a beautifully-made, vast array of patterns and shapes, all are PUL-free.
TCS Eco (based in Scotland) has an amazing array of patterns, various lengths and materials / thicknesses of pads and all are PUL-free.
Red Queen Cloth on Etsy also sells PUL-free, beautiful-looking sanitary pads (in a choice of light, medium, heavy or super thickness). The listings specify the combination of Zorb / bamboo fleece / flannel used in each.
Guiniveres on Etsy is another PUL-free sanitary pad seller with an eye for quirky fabrics and practical filling-material combinations.
Alternative Girl on Ebay relies on Zorb alone, making the pads more affordable - they are probably better suited to those with medium flow periods. Heavy periods really need a combination of pad fillings when PUL (plastic) isn't used.
For those wanting thin pant-liners / low-flow pads, these PUL-free ones from Bain and Savon come in some gorgeous designs - BUNNIES, SKULLS or PINK SKULLS would all be practical colour choices.
For more information about the materials used in cloth sanitary towels, from plasticky PUL to the amazing absobancy of Zorb, see this excellent 'Cloth Pads' article which I found by chance whilst fact-checking on the web.
When planning to switch to reusable period pads, you'll soon realise that you will need a waterproof-and-washable, dark coloured, small bag to put the used pads in when out and about. Ideally you would have a couple of handy waterproof two-pocket pouch bags to store both dry and wet items. Why two bags? One to use and one being washed/dried, so that you are less likely to leave the house without a suitable bag. The lovely folks at Floating Lotus (in Warwickshire) sell a two-pocket wetbags for £5 each, including delivery, you can email them at floatinglotuspads@hotmail.com. NaturallyLady on Etsy sells small two-pocket wet bags too. You'll also need a washable bag / lidded box next to the loo at home to put used pads in, before rinsing them in COLD water to avoid staining (not an issue if you pick uber patterned pads of course) and then tossing them into the washing machine. A Bambino Mio wet bag in the red (starry night) design does the job very nicely.
It is quite a pricey step this one, but if you add up the monetary cost (not to mention the environmental cost) of using disposable sanitary items you will realise that you will quickly start to save money. It is also much nicer (and much healthier) to have natural fabrics (cotton / bamboo) against your skin. Once you get used to the extra hassle of storing used pads and then washing / drying them, you will be pleased that you took this eco step.