New bike: the quest begins

I went bike shopping with Robert and OGMP (the Original Michael P) today. We went to 3 shops, and none of them had my size in any of the bikes I was interested in.

I have two options: I can get a "Road Bike", or I can get a "Triathlon Bike". But this is what makes my head spin: the prevailing advice is "if you want to get a bike for triathlons, don't get a triathlon bike.". Tri bikes are designed for flat, straight courses where you can just drop down into the aero position and stay there. They are not good for hills. Many people have two bikes; a road bike for when they are out training doing hills, and then a tri bike for races. Yet it never seems to occur to these salespeople that maybe a triathlon would have hills. What kind of races do I do? Malibu Triathlon: short hills. Arrowhead: nothing but hills and sharp turns. Ironman Coeur d'Alene: hills. Wisconsin '09: worse hills. Wildflower: Mega-hills. So my question is this: where are all of these flat triathlons people are doing where they can actually use a tri bike? Because obviously I'm signing up for the wrong races.

At the first shop I rode a Cervelo P2C. It was a little big for me (I need a 51-52, they had a 54), but I think I kind of liked it. Shop #2 was a major Specialized dealer so I rode one of their bikes I never heard of. I didn't like it, and the salesguy kept asking me what exactly I didn't like about it. Over the past 4 years, I've ridden only one bike so I don't know the vocabulary to describe it. Was it stiff? Not responsive? I have no idea. Didn't like it, end of discussion, leave me alone.

Apparently I got a little snippy at shop #3. They had a 54cm Cervelo I wanted to try (I don't remember which model). I told the saleslady "I'm interested in this bike, but I'd like to test ride a 52. Do you have one in that size?" She went away to check, came back and told me "we don't have that bike in that size, but we have the frame so we could build you a bike." I didn't understand. Would they build me a bike so I could come back tomorrow for a test ride, or was this only if I wanted to buy the bike? So I asked her "well what do you mean you would 'build a bike'"? She wasn't helpful: "If you want the bike, we can build it for you."

"I don't want to buy a bike without riding it first. Would I be able to ride the 52?"
"We don't have the bike, but we have the frame so we could build it for you."
"OK, but what does that MEAN?! Can I ride it?"
"If you want the bike, we can build it."

Just forget it.