Gate looks Great.
The thing to understand about the chevrons is that the bottom two are never used. All gate addresses utilize 7 chevrons: six coordinates in space and the seventh which is the ID of the gate you're dialing from.
So definitely I'd not light up the last two on the bottom. You might have a stand to support the gate which obscures the bottom chevrons anyway, which is how the gate usually appears on the show (either sunk into a platform or clamped from the sides with steps leading up to it, as in the SGC).
There is one and only exception to the 7 chevrons thing, and that is for the spinoff "Atlantis" series they decided that the 8th chevron would light up for travelling to another galaxy. The 9th chevron has never been used on the show.
Now if your gate just sits there and lights up chevrons, you actually have a model of the Gates found on other planets. The gate at Stagate Command on Earth also spins its inner ring (with the glyphs on it), when the last glyph stops at the top chevron, the chevron does a little mechanical in-out maneuver to "lock" into place.
Sometimes when advanced aliens activate the Gate, they just gesture at it and all SEVEN chevrons light up simultaneously with no spinning or entering of coordinates.
As to your question, what order do the chevrons light up,
[EDIT: I popped in the DVD of "Children of the Gods", which is the pilot episode for the series, and according to the monitor screens, the visible chevrons on the SGC gate (ignoring the bottom two) light up in this sequence:
2 o'clock
3 o'clock
5 o'clock
7 o'clock
9 o'clock
10 o'clock
and finally
12 o'clock
COTG also clearly shows the SGC gate chevrons only light up on the FRONT side, the back of the gate remains unlit.
Here's a page on gate technology.
http://en.wikipedia.org/wiki/Stargate_(device)
And the Stargate seen in the movie has some differences as opposed to the series.
* The chevrons in the Stargate film do not glow as they do in the series.
* The top chevron on the film's Stargate is different aesthetically than the rest of its chevrons. In SG-1, all the chevrons on a stargate are visually identical.
* In the film, to "lock" in a stargate symbol, each chevron "pops" or "clamps" the symbol in question to dial it. In SG-1, only the top chevron "pops" when dialing an address, while the other chevrons merely light up and do not clamp.
* The symbols on the film's gate are engraved into the surface of the Stargate. In SG-1's universe, the symbols protrude from the gates' surface.
* In the movie each stargate has a unique set of 39 symbols, but in the series each gate has the same 38 symbols minus a single point of origin symbol that is unique to that individual gate.
http://en.wikipedia.org/wiki/Stargate_(film)
- k