Good hardware choice.
Juice & extra parts:
Extra is always helpful. Maybe an extra box of 5 blank carts, but extra atomizers will be needed sooner or later. May as well save on shipping while you're at it and get the extra attys.
Juice, I'm going to break your heart here. None of them wil taste exactly like your cig. Sorry man, but I'm really happy about that. When I started I wanted one that tasted like my Non-filtered American Spirits, so I feel for ya, but something weird happened along my way to finding that perfect cig taste, I found something better. It may make no sense right now, but nearly all of us have made the same conclusion.
For juice I recommend getting a selection of small bottles. Different strengths AND different flavors. Get the cig flavors, get the cigar flavors, maybe even get the pipe flavors, but do yourself a favor, get a flavor that just sounds weird to you. At least one flavor that you cannot imagine wanting to smoke.
And I recommend this because so many of us, myself included, discovered the juice that worked for us with a flavor that we least expected to work. That one flavor that makes you wonder why you'd want another cig ever again.
Now, for vendors, please see the reviews sub-forum and see if anyone sounds good to you. Check out the suppliers forum and see if an ECF vendor is running a special that fits you.
Welcome to ECF and enjoy your new journey!