Laser Engraving on My Kossel Clone/ Expanding My Build Area

[ctcollins9]

OK, so I have got 2, things I really wanna do. First, get a laser, but I'd like to put that aside for now, and instead try to expand my XY build area. If I am going to do this, I know I need at least 9 of the t-slot rails in longer dimensions (but do I also need more rails to make the build height taller also for this to work?) And longer traxxas rods. I would like to make it atleast 3 inches longer in printable XY area but If I am going to spend the money to do this, I think is would make sense to expand it maybe 5-6 inches in case I ever needed it. Also, if I were to get longer t-slot rods, how do I know how long my traxxas rods need to be? I have found several places that supply glass, aluminum, or acrylic beds that would fit the printer pretty fine if I expanded it. Thanks.