Unlike walking into a high street store to look at televisions, there are very few showrooms and retail outlets where you can see projectors working; despite the fact that projectors are often the best choice for homes and businesses.
There are a few things to take into account when choosing the right projector for you and these are the brightness (or lumens), the throw distance (distance between where you want to want to install the projector and your screen, and size of viewing image you want.
It is also worth doing that extra bit of research to find out the lamp life (duration of) and price to replace. Lamps are often very expensive- a bit like buying a printer and checking out the replacement ink costs!
Once you have this information most projector producers have on-line calculators were you can type in the above information and they will provide a list of projectors that will do what you need