You really need a diesel... My R25 is over 11,000 pounds all up on the trailer, your 29 will be even more... A gas motor is going to struggle with that much weight...
I am partial to the GM/Duramax engine, Silverado 2500HD... My current boat hauler is an 08 crew cab with the short box and a hard (folding) box cover... I believe that the 2500HD will handle your boat... But if you intend to climb Pikes Peak with the boat on a regular basis then the 3500HD would be indicated... I would advise staying away from a dually for pulling the R29...
If you expect to be pulling on winter roads or using slippery ramps then a 4X4 is best... I went with a 2WD because of the better mileage and improved ride and shorter turning radius and the lower operating costs... I carry a 5 gallon pail of dry sand and a scoop for the once a year slippery ramp...
I do not intend to be pulling my boat towards snow and ice - no, no, no!!! The other direction, fer shure.,..
If you are considering a new diesel truck, Ford has a new engine design for 2011 that is claimed to be good and have better mileage than 2010 due to the required Urea injection system and more power to boot...
The 2011 Duramax/Silverado is supposed to get better mileage for the same reason and has a significant increase in power over the 2010... At this point I am wishing I were buying a new one now as I would get a 2011 Duramax...
Dodge trucks I know very little about so I will not comment... Used trucks are always a better bang for the buck...