Interesting link. Written in 2005; I don't see any follow up on their website.
While also not a big dyno junky (maybe just because I don't have one), it's interesting to see 5 hp from a canister change, but not much difference from crossover change. Or even a 6 hp drop on the top end (from that link's charts).
It would make me confident to fit some cans that I like the looks of (oval, round, reverse megs, stainless, aluminum, carbon fiber) and wait on the crossover.
If you are going from the stock LaFranchoni twenty pound canisters, you will absolutely love whatever you choose. They'll sound, and feel, great. If you love the look of the reverse cone Mistral - go for it!
You can always fit a different crossover on later. The tuning isn't that critical as long as the CO is set. Have the dealer get that zeroed or 3.5%.