cheap CX build: looking for suggestions

[snapster]

Hey All,
I was thinking about making a cheap all-purpose (commuting, maybe some longer rides, on trails, on roads, etc) bike. I've got a single-speed "beater bike" for such, but it's not very fun, and not really versatile; and it's frigging heavy. Not sure how heavy, but it would be cool to have something lighter, sub-20lbs I would hope. I'm not sure how light I can expect to get given a low budget.
So my thought was maybe use a cyclocross frame; I recently had the pleasure of trying out a 1x11 setup on a MTB, and something like this would be more than sufficient for this bike. In fact, I was thinking something more like 1x10 to save cost; I could get like an older SRAM 36-11 cassette or something...
Anyway, I don't know anything about cyclocross frames. Does anyone have any good suggestions for a cheap aluminum frame that I could work with? What about wheels?
Thanks for any (non-snarky) advice

[Dalai]

Which country? If the UK, Ribble cycles have a cheap aluminium CX frame...

[Marin]

What's your budget?

[snapster]

country = USA, budget = I don't know...<$800, hoping to go even cheaper. I kind of want to do a "let's see how good of a bike I can build for quite a small amount of money."
Also, I'm happy to go with used stuff.
Some CX questions: does someone typically get a CX frame with the same geometry as a road bike? (primarily, I'm referring to the "stack" and "reach" of the frame, which I feel is most relevant for fitting the frame to your body (as opposed to other geometry aspects, like fork angle, which are more relevant to bike handling, etc))
Also, does everyone just use "brifter" style shifters, like on road? Or in CX are there other shifter options?

[Marin]

You could probably do a Chinese carbon Cx with 2nd hand 105 or new Microshift gruppo with Mavic Aksium wheels for 800.

My Cx/commuter/tourer has the same top tube length as my road bike, stem is a bit shorter.