BRAND NEW NANO TANK SETUP - QUESTION PLEASE :)

Hello:

I want to know what to do next. ... I want to know what's the best
route for my live rock, simply because I was told that this is gonna make or
break my nano tank setup.
I have a 15 gallon Hagen, 30 lbs of crushed coral, AquaClear 150, extra
powerheads to put in place when needed, Instant Ocean salt at 1.024. For
Lighting I just bought a 24 " Coralife Lunar Aqualight, Deluxe Series- 1 65
watt True Actinic 03 Blue, 1 65 watt 10,000K daylight, 2 3/4 watt
Blue-Moon-Glow led's. My wife lost her mind when she seen I had paid $244.00
for that light strip, but the reason I did that was for the fact that this
light will allow me to place anything in there and it will grow. I know that
there are certain corals that don't do well in a nano tank, so I'll make
sure not to purchase the "wrong" things when the time comes, but now I need
to know everything I can about Live Rock because that is my next purchase.
One person told me that I should not buy expensive rock because it's
all gonna die while the tank cycle's. Just in case he's right .. I now have
two Mollie's in the tank, for the cycle process. They have been in there for
one week, but the tank has been running for three weeks with just the water
and crushed coral. ( I wanted to run it like that for weeks to get used to
the evaporation amounts on a daily basis).
So, can I get some input on how to buy Live Rock ? I only have two
places in my city to purchase it, one is a rip off and the other is a small
LFS that has some knowledge of Reef systems. What do I look for when
examining the LR in the store?.. it goes for 13 to 14 dollars a pound here
in Nova Scotia, Canada. How do I know if the rock is dead? ... these are
basic questions but I have been reading up quite a bit on nano reefs, but
some of my questions are not answered. One site said to buy FIJI rock cuz
it's the best .. how would I know that? ... you get my point ... please tell
me what to do for my next move into the salt water setup.

PS: I have an 80, 33, 20, and 15 freshwater, brackish already setup here in
my home . I've had tanks for 20 years, I just have never gotten into SW
setups because of the price.