I use one of these which is excellent. You may be able to pick one up at retail for the price you are looking at, but they genarally are around £300
Ebay is an option if you are comfortable using that route.
Pleae note the link is just a quick search, not a recommendation to use that particular vendor!!
The phone itself is excellent. Windows based PDA with pocket word and excel, simple to use, bluetooth for connecting to hands free, or in my case to tomtom for sat nav use.
I have had this phone (althogh branded as T Mobile MDA Compact) for about 14 months with no problems whatsoever. There is a newer version called the K-Jam which also has wi-fi, but this will probably be outside your budget.
click here are very good for this type of thing.