Note that you can always get one more order for free, because the odd-numbered pole is real-valued, meaning it doesn't need a gain element to make it resonate, it's just a passive RC. Unfortunately the impedance of adding an RC, changes all the other values in the filter stage (of course!), so you need to calculate the values right the first time. Ah well. That's what calculators are for!
You may find a 3rd order filter is adequate, in which case you only need one opamp. Otherwise, you might as well go for 5th order with two opamps.
This calculator does 3rd order:
http://sim.okawa-denshi.jp/en/Sallenkey3Lowkeisan.htmYou can adjust the calculated values for a somewhat lower Q, then using the 2nd order calculator, adjust for a somewhat higher Q; the product of both (the response of the two stages cascaded) should approximate the desired overall filter response.
You may consider the MFB configuration for the higher-Q stage: S-K is more sensitive to component value variations, which gets more problematic at higher Qs. There's no other major outward difference, both need just as many resistors and capacitors, so it's nice to have the choice of both.
Otherwise, I think Analog Devices has a filter tool that does this? Probably any active filter design tool will include the 3rd order trick, and will be able to calculate the correct values for both stages together without having to guess about each.
Note that you want a comparable highpass to avoid doubling up on low frequency content, i.e. to keep the overall response flat. There may be something about phasing as well, because unfiltered mids/woofers will interfere with the sub, causing peaks and dips. Which will vary by location of course, because sound.
Tim