Please don't take this the wrong way... But, I've seen "BMW, Clean Cut, Business Owner, Business/Credit Cards, Work With Doctors and Sam Adams" all in the first few pages of this post... Don't try to dirty yourself up to look the part in order to buy some weed... It'll work against you, you'll look like a cop trying to go undercover for the first time.
I hate to say it. But, unless you go homeless for a while, it's going to be hard for you to get over 'that' look.
And again, don't take any of that the wrong way... You and I are in the same boat. I've moved to a new city and I know NO ONE! I decided not even to try and started a secret little room of my own. You sound like you have the means to put a very nice one together... Now all you need is a shit-load more Sam Adams (I suggest Octoberfest) and about six months worth of patients.
Your older home will hold the load of at least a 400w HPS as long as there's not much, if anything, on that fuse with it. I'd suggest getting a switchable ballast so you can start out with a MH for vegging and then throw in an HPS for flowering. You'll be loving life after it's all said and done. Heats not that big of an issue with a 400w. Hell, I had to put a heater in the room with mine because it's too cold in there.
Before you order anything or take my advice (or anyone else's for that matter) read this cover to cover...
GrowFAQ There's a million and one different ways to do this depending on what results you're looking for and what limitations your house has. That will answer most if not all of your questions... The ones that it doesn't... ask away and people will come out of the woodwork with advice.
Good Luck and keep everyone informed as to what's happening by doing a Grow Journal.
(Edit) P.S. Take your trip to Amsterdam after you've done a grow. It'll be more worth while at that point. You won't go for the pot, you'll go for the seeds. Though the pot will be very nice!