Any projector works for BowSim 4D but of course there are some that do the job better than others. Especially when it comes to the format or image ratio. Each of our customers uses BowSim 4D in a slightly different environment. It is important the projector meets your requirements.
In our online shop we offer a few recommendations for good quality projectors we really like. Those are probably not the best for every customer but from our experience great value. If you find a good second-hand projector or local or online deal you will probably save a lot of money.
We recommend to shop around a little. Sure, you will find the projectors we recommended cheaper elsewhere and maybe other projectors that offer even better value. Talk to a local or online specialist if you want to do further research.
All in all, it is a very straight forward approach. If the projector you choose is bright enough and you choose a WXGA (or any other 16:10) image ratio you are winning. Projectors with other image ratios will still work but some of the brightness might get lost.