APT wrote:
If you insist on the Suburbans, I highly recommend a 3/4 ton. The 2000-2006 come with either 6.0L or 8.1L. The 6.0L offers more capability and similar fuel consumption so the 5.3L in the half tons of same generation. The 8.1L is nearly unmatched for towing power, at the cost of lots of fuel. That's great if dedicated tow vehicle and was my first choice before buying new in 2011.
Not to beat the Avalanche dead horse, but you raise a good point: unlike the Suburban, the Avalanche was not available in 3/4 ton after 2006. Also, from '09 up the Suburbans (and Avalanches) had 6-speed transmissions. Not sure what that means for towing. Mine's a 4-speed.