i have heard that i should stay away from leisurepro.com (from a guy i know on a car forum who dives) but havent heard anything about scubastore.com. i ask b/c the aqualung calypso/titan is $78.29 from scubastore.com
Welcome, if you are anything like me soon you spend way to much money and be playing underwater when you should be doing other stuff. I will not say whether or not to buy from LP/scubastore.com for aqualung or scubapro because I have not done so but if you look around this site you will find a lot of threads discussing this issue.
http://www.scubaboard.com/forums/new-divers-those-considering-diving/281974-leisure-pro-pricing.html
http://www.scubaboard.com/forums/regulators/265741-buying-leisure-pro-vs-local-dive-shop.html
It should be noted that since you got the reg second hand you probably won't get the warrenty on it, so if warrenty is the only thing your worried about it's a moot point.
What I will recomend is that you wait to buy a BC until after certifaction and several dives in various conditions. I didn't do this a found myself getting a new BC shortly after to better match my diving conditions.
As for listening to a master Chief it depends, I had a COB/CMC that didn't know his *^$hole from his mouth and couldn't do a thing, but a couple of master chiefs who where decent.