Another Alienbees Advice Thread

A family member has recently asked me to shoot her wedding so I am now in the market for some lighting. I have a limited budget ($600 or so) and I am trying to get the best bang for my buck; which is why I am eyeballing some "Bees".

Here is what I'm gonna need (from what I can tell):
1 or 2 monolights
Light meter (I think I have decided on a used L-308s for $100)
1 or 2 heavy duty stands
and maybe a cheap Amazon softbox for bride photos (if I have any funds left)

The ceremony will be close to sunset with group pictures happening after the sunset (hopefully start 20-30 min before official sunset). The largest group should be about 10-15 people.

Now for the lights...I was seriously considering buying a B800 based on the expected output guide on Paul C Buff's website ( http://www.paulcbuff.com/output.php ), but I found a local guy here that is selling 2 B400s with 2 of the Paul C Buff head duty lighting stands ($80 per) for $400 total.

The long and short of it...should I saved some coin and buy just one B800 and a cheaper stand (brand new), or should I get the 2 B400s for a little more and enjoy 2 lights for future projects? Can I just put the 2 B400 next to each other to equal the power of a B800? (sorry if that sounds stupid)

Other info:
1. I shoot with a D90 (which baselines at ISO 200)

2. I prefer to shoot smaller apertures for portrait and group (with opening it up when needed)

3. I have traditionally shot with available lighting, only breaking out the TTL (CLS) speedlights (1 SB-700 and 1 SB-600) when necessary, but I have been looking to do more "studio" work from my garage; so I was planning on buying eventually anyway, but the wedding drove me to make the decision faster.

I heard that buying 1 light is best when first staring to really learn studio lighting...any truth to that?

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Thanks,
Mike