Hi RoyC,
I don't think you can go wrong with The Ball Python Manual. Very good reference.
As far as some of your remaining caging questions, a lot of this is coming down to personal opinion, which is fine. No worries.
I can tell you my opinion on why I personally don't like the front-opening doors of the cage your are talking about; I have kept some quick-moving snakes before, and I have seen the quick-movers be very difficult to safely put away in a cage that has the opening in the front. A lot of them can get pretty close to getting pinched - heads or tails. I just don't like it. Ball Pythons of course are more like the ultimate couch-potatoes of snakes, and shouldn't give you so much trouble there. Should you have one with the occasionally-fiesty moment or two, a front-opening cage - and more so, a split-door setup that opens in the front - doesn't give me the feeling that I can control the situation as well as with a cage that opens on top. My other concern is that I would guess by looking at the design of those glass doors that they may give when the seam is pushed - and if so, a BP could potentially push its way out of them. Couch-potatoes they are, but they are still strong, and they are still snakes - and there is no better escape artist in this world than a snake!
If the doors don't give when pushed, and you still like the way the doors open, then don't worry about it - I'm just trying to point out what I have seen and how that has shaped my opinion. 
As for the size of the cage, I LOVE this Aquarium Calculator! From that calculator, the cage you are talking about would be 33.421 gallons in volume - and that is NOT bad!! I was thinking the cage was quite a bit smaller than that. Yes, ideally, a cage that is short and wide is best for a ground-dwelling snake, but as long as the floor space ("footprint" ) of the cage is adequate - as it appears to be - you should be fine.
Try looking up what I was talking about as a Critter Cage if you aren't familiar with them. They can look very nice too, and if you can find a nice deal on a used one, they get even nicer!
(I am really cheap) I like their open-from-the-top design, and that they are pretty much child-proof. I think the black edging also makes them look fairly nice.
I also looked up the Exo Terra glass terrarium you were talking about (as opposed to the Habitat Kit)... did you see they have a short & wide model (PT-2613)? If you haven't already made your purchase, that model looks like it would be the right size for an adult BP... maybe down the road if not now.
What do you intend to use for a heat source? Heat lamps cause a lot of drying issues - and the taller the proportions of the cage, it seems, the more of a problem this can be. I do use heat lamps in my cages, but that is more because I know they work and it is hard for me to change; I am slowly changing to heat tape... but while I have lamps, I have to mist cages daily to maintain proper humidity (I also use terra cotta flower pots for hides, which nicely release humidity over the day). WalMart sells some nice, ergonomic (& cheap) little spray bottles in the hair care section.
Then finally, you asked a lot about where to buy your snake. I currently live in central Illinois, so I can't tell you a thing about the East Bay Vivarium or anybody local to you.
You say you really like the black-eyed leucistics (I'm abbreviating this: BEL), which are pretty high-dollar. I just glanced at the online classifieds here, and Fires seem to be right around $1000, give or take some. The Fire morph is of course the heterozygous form of the BEL, though to the untrained eye, they look a lot like a Normal BP. I still think that's a bit too much to spend on your first pet, but that option is open to you, depending on your budget, as down the line, a Fire bred to another Fire would produce your BEL. Pastels are fairly affordable now as morphs go, too.
You also said at one point that you wanted to start out with a Normal. NOTHING wrong with that approach either - they are MUCH MORE AFFORDABLE - and there are plenty of breeders who would be more than happy to find a good home for a Normal, and would likely be willing to give you a good deal. If you even think for a second that you might want to breed BP's eventually, get a female. They can be a little harder to get a hold of sometimes, but as they have to be about 3 years old before they can breed (while males can breed around 1 year), the female should be the one to get first. Females can also be harder to find to buy as adults. If however, breeding is not anything you are interested in, there are lots of Normal males that need good homes. 
Once you know where you stand on that, I would say that the swap would be your best opportunity to meet and talk to breeders, and ask any questions you can come up with. Like I said, I don't know EBV, but it's my guess that you will get the best deal at a swap - just ask good questions and look around a lot before you get attached to an animal and buy it!
Good luck, and I hope this helped, even if it got LONG 
~Rebecca
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1.0.0 Dumeril's Boa '04
1.1.1 Ball Pythons
[1.0.0 '05 Orange Hypo (Specter)]
[0.1.0 '05 Het Orange Hypo (Sylvia)]
[0.0.1 '03 Normal (Sue)]
0.2 American Pit Bull Terriers (40lb darling lap dogs:Brandy&Mara)