It's a long way, but good thing is - by the time HF movies are done, Tsukihime remake would probably be out.
Still, I'd rather see an Ataraxia adaptation first. Not an entire show, maybe OVAs or one big movie. I can't say all the SOL scenes would be dearly missed.
Then a Tsukihime adaptation - a mix of some routes, not a straight adaptation like UBW. And then some OVAs for the rest. Although that's unrealistic. Ufo aren't too keen on big changes to the plot. They're probably afraid of doing what DEEN/JC Staff did.
A Prototype adaptation would be nice too. I don't really care for the order of the rest.