That's so funny. I went thru the same exact stuff last summer (girlfriend getting sick of it/me, constant web searches, trips out to the sticks to find out no boats in stock...) I'm in Chicago, &, similarly to your situ, dealers actually told me that they mainly stock the big glass rigs because everyone sees them on TV & they want what Mike Iocanelli & co. has (even though most have no business in a 14ft jonboat). That, and deep Vs are big here, since I'm on the big pond (Lake Mich).
As far as price, the Alumacraft was actually one of the higher priced I shopped. Never got a price on the Triton (since the dealer was so far), but it was more $ than others (I looked at Fisher, etc.) & I thought more than G3 (I always see good prices in their ads, but, like I said, didn't really consider them at last) but it looks like about the same $ after all. I have a 125 merc 2-stroke on my 185, and I paid not much more than your 23k. Might've considered a 4-stroke or the 150 if I was building one, but that's even more $ & they happened to have this boat/motor combo in stock. Actually, if I was building one, I'd prob get an Evinrude etec (4 strokes are much heavier/bigger & the new efis are close/sometimes better in fuel econ & emmissions.) Had an old Johnson/Evinrude that I loved, & a Merc that I had probs w/ (again w/ the Tracker!) But my new Merc is pretty sweet so far.
The 115 should be fine, as mine is probably heavier w/ the thicker guage hull (.102 -- industry standard is .100) plus your 180 is 1/2 a foot shorter. Mine jumps out of water & cruises d**n close to 60mph.
Was just kidding about keeping yours outside, but am curious, is the G3 that much narrower? Both brands look almost identical & even heard once that the AC was based on the G3 layout (or vice versa).... I just looked at the G3 website... looks just like mine (storage, layout, step seats,end w/ the gas cap, everything!) Only I don't see a recessed step to the front deck. & it's only 2" less beam! Move that truck out onto the drive & sqquueeeze 'er in! Sweet. Congrats.