You're not too heavy for a 157 but i don't know what it's like being 6'3" (i can only dream). What size boot do you have? and what have you ridden in the past? Lib techs ride longer for their size and the effective edge on the t.rice is quite large. You're probably too tall for a 154 now that i think about it. Based on you're weight i question whether you need a 161.5 in aus.
I still maintain that you would probably benefit from something a little softer.
I'm in a similar situation to you only i'm about a foot shorter, but with assistance from these forums i'm looking at the nitro rook, forum destroyer and Arbor Coda.
The machete looks like a really good board but again pretty stiff probs more of a jumper...i'll leave board suggestions to people who have had experience on them.