You are right about the mileage required - 135k for busienss class is bang on for 2. The most likely route to MCO is via FRA - LH usually had decent availability... however, they drip feed it out and then dump the balance about 6-8 weeks out, so you may need to be patient and do a last minute job. The down side is that the YQ (fuel surcharge) is frightening, and when you add Gordon Browne's little present, you may not be prepared to pay that much tax. In that case, you could book a cheap flight to FRA in economy and start your redemption from there.

Beyond that, you'd be looking at CO to EWR and onwards - and in my experience, the seats are as rare as hen's teeth.

Have a look at the bmi forum sticky and learn about the ANA tool.