Consider using an appropriate UTM zone for your region. UTM has a linear measurement unit in meters which will work with QChainage (as per your other question). Alternatively, if their is a national mapping agency for your region that has specified a CRS (e.g. for the UK it would be OSGB), use that (so long as it has meters as the unit of measurement).
You can use this facility to search for potential CRS for a given area (draw your area on the map and when you close the popup the coordinates are entered in the form for you - then click search). You will get a lot of answers but it can help narrow the field and each suggestion has a link to its documentation.
And/OR refine your question to stae your geographic area of interest and you'll get a better answer.