In the UK there are a number of commercial playground suppliers. Those I can think of off the top of my head are:
Playdale
Hags
SMP
Wickstead
Eibe
Kompan
You can request product catalogues from these companies, plus find some of their products online.
Surfacing is a major cost. When looking at equipment you will be able to find out what the Critical Fall Height of that equipment is... that will determine the depth of the surfacing needed. There are various types of surfacing, ranging from Sand to Wet Pour. When looking at surfacing consider the daily/weekly maintenance it needs and the cost of repairs, consider animal activity.
There is a large tradeshow coming up - IOG SALTEX held in Windsor 8-10 Sept 2009. While not aimed specifically at the playground market, several of the companies above usually attend - also providers of playground surfacing and general landscaping.
The problem I suspect you will have is money... what budget do you have? The costs of commercial playground equipment is a lot more than the stuff you would get for your back garden.
Do you need commercial grade, or can you get away with something a bit lower? If the playground does not have public access... then your insurer may not require you to have commercial grade equipment. Look into the insurance side of things... look into what access the playground has, such as when the pre-school isn't open. Also look into any requirements there are by the pre-school regulator (Ofsted if in England - does EYFS specify outdoor equipment suitability... not sure it does: "Outdoor and indoor spaces, furniture, equipment and toys must be safe and suitable for their purpose" - suitable for their purpose I feel is open to interpretation.
Consider the provision of shade. Many playgrounds in my view lack shade.
Playground Safety - ROSPA are good to contact for advice. They have downloadable leaflets plus provide consultancy services.