I use thermoplastic tubing and like it because it doesn't "kink" as easily as silicone.
(I have both silicone and thermoplastic)
The march pump will not introduce enough air into your wort to worry about... If there is air in the pump, it won't pump so no air in the wort, when it does start pumping, your flow will be pretty free of air (not enough to cause a problem).
As for temp ratings... thermoplastic will handle the liquid temps of brewing just fine. The only place where I have had any concern is when a hose ends up in close proximity to a burner or super heated keg skirt in which case, silicone is only gonna hold up marginally better.