You could go the inexpensive route and add some passive inductance to form a low-pass filter. A coil (inductor) of about 0.3 mH wired in series with the positive or negative lead of each of the Neopro's would give you a 6dB/oct LPF of about 2khz.
Depending on how the 10"s are installed you might not need a lot of filtering on the higher end. Larger speakers will naturally roll-off at higher frequencies, and "stacking" them by using multiples will further reduce the off-axis high frequency information by decreasing the beaming frequency.
If it was me I'd prefer to have some kind of active filtering though, either through a DSP or an amp capable of higher frequency points with the crossovers, but If I didn't have anything at my disposal I'd still install everything and set it up like I described in the above post just to see how it sounded.