Road vs Hybrid geometry?

So im looking to build a flat bar commuter, already got some Ultegra caliper brakes and an EC90 flat bar, ideally i would like a roadrat but i already have the calipers and really dislike v brakes.

So my question is do i have to look for a hybrid specific frame ala Sirrus or is the geometry not so different that it would not be to bad to just run a normal road frame with flats instead of drops.

If hybrid frame is the way to go any reccomendations?

Ta

Short answer – hybrids are a bit longer in the top tubs due to not having the handlebar extension effect you get with drop levers and drop bars.

But theres loads of variation, with some more like 29er MTBs and some effectively road bikes with flat bars (and similar levels of tyre clearance).