'97 is a good year!!
There are a few upgrades that will gain more towing power with them, custom tuned chip, gauges and intercooler to name a few. The 5 speed trans is very capable of hauling whatever you want with a good clutch, you won't hurt it. I have set a lot of guys up at around the 400RWHP mark with these trucks are they are happy with the power and economy.
A few things to look for if buying; Make sure it does not "huff" smoke out of the oil fill cap, if it does it might have a compression issue, some smoke is ok just don't want pressure. Also take a good look at the stock air box and make sure all the clips are there holding the lid down, they have a tendency of breaking and the owner ignoring it and the dust will take out the turbo wheel/rings. The stock downpipes in them sucks also so a good starting upgrade would be a 4" exhaust and a good intake.