He did say up to a .61 for power so that puts a limit on things, so does the ARF but there are a lot of good selections in ARF form. As Speed mentioned, it is a lot more about the planes set up then anything. As a builder I had some good choices in that size department back in the day so for pattern type flying I liked the 60 size Kaos and Dirty Birdy and for IMAC it's hard to beat an Extra, Sukhoi or Yak. These three planes are easy to locate in the size ARF you are looking for.
My old Goldberg 60 size Extra has a 68 inch wing and was a good IMAC plane before all the judges went blind and can no longer see any plane smaller then a 40%. Fantastic plane but it's powered with a 120 four stroke. The 60 two stroke just didn't have the pull I liked. A 60 will fly it but not well.
Just look at the 60 size ARFs and pick out the one you like. I like Aeroworks planes, pretty good quality but a bit over priced but you do have to pay more when they use real glue.