Check out www.smarthome.com or www.homeautomation.net and they have many pages that describe the different switches available.

I don't know of any x-10 wall switches that won't allow you to turn the light on/off at the switch or by remote.

I think the 2way you are getting confused is the ability of the switch to only receive x-10 commands (1 way) or the ones that receive and transmit x-10 commands (2 way). Most of the time you will not need a switch that can transmit. some examples of one that transmits might be where it reports to some other switch that it is on. A computer checks to see if the hall light is on at 2am and if so turns it off. You could just have the computer send an off command regardless with a one way...

When you see a 3 way or 4 way description, this will refer to a light that is controlled by more than one switch. You probably have a garage light that has a switch at one entryway to the house and another switch at the entry way from outside. The two switches work together to turn the light on or off. This is a 3 way switch. for normal non x-10 switches you must buy a special 3 or 4 way switch for these installations. However with x-10 you can use the same switch regardles of whether it is a 3 way or 4 way, you just buy a companion switch for the other location.

I hope this help and was correct. I am new to this as well.