there are plenty of lower REAR tie bars available for the crx. i have one (pilot motorpsorts brand).
as far as front lower tie bars, hardly anyone makes them. i have searched the net and the only two companies i know of that make FRONT lower tie bars for the crx are: cusco and bennen. not even spoon or mugen make them, so i am thinking maybe the crx doesnt need a bar there? they make them for other models, just not for the crx.
the difference between a front strut bar and a rear strut bar in MOST cases is...
front strut bars are usually curved (this is to allow clearance for part of the engine that may be in the way of a straight bar).
rear strut bars are usually always straight and flat. never seen a curved one.