Ariane V is a fairly straightforward build... get your hands on a copy of Peter Alway's "Rockets of the World" (or the appropriate supplement) and it'll have the scale data in it, or do some searching on the web... Basically an Ariane V is a shuttle stack without the shuttle, just slightly different proportions...
BTW, Ariane V doesn't have "3 boosters", it has a pair of solid rocket boosters and a core vehicle powered by a liquid hydrogen/liquid oxygen burning Vulcain engine. The boosters get it off the pad and accelerating, then they burn out and separate and the Vulcain pushes the core on to orbit, or near orbital velocity, where the second stage takes over and completes the orbital insertion (or propels it on toward a geosynchronous transfer orbit, with an apogee at 22,300 miles out in space. The stage performs a second circularization burn at the end of the Hohmann transfer to inject its payload(s) into geosynchronous orbit (GEO).
It's a possibility... many of the parts (except the booster nosecones, and they could probably be modified from standard balsa cones used on the shuttle SRB's) are used on other Zooch kits... but I don't think that an Ariane V is in the running, honestly. BTW, an Ariane V will not fly without flamefins of some type, not without active guidance... using the boosters as "cone fins" won't work because the rocket is asymmetrical in the pitch and yaw axes, meaning that even if you go the CG far enough forward by using extra noseweight, the rocket would only be stable in the pitch axis... it would have no stability in the yaw axis due to it only having 2 SRB's on either side. Besides, it'd be SO heavy it'd perform like a real dog... better to just use flame fins and do it right in the first place...
Someone mentioned the cargo SLS... that's another good possibility. Such a kit would use common parts with the other kits and be a pretty straightforward thing to do.
Course, I'm just whistling in the wind like everybody else... When the Doc (Wes) has something to tell us, you'll hear it here first I'm sure...
Later! OL JR