What type of material should be used for sole plates on screened in porch?
Could be composite material.  Pressure treated 2x4 would work.  An adhesive with the appropriate fasteners will anchor it well.

Don't know of other kits besides screentight.  I would check your local home stores and online.  You can roll your own but the end result may not be as taut as you'd like.   

Good luck.