Before going on any Tour I would suggest checking all the basics, such as a good working electrical system and and cooling system.
Make sure you've got a good battery, a good working alternator, check all your earthing points and earth straps are in good condition.
Make sure your cooling system is working reliably. ie It maintains a steady temperature if left idling in traffic and the radiator cooling fan comes on. From cold, you should see the temp gauge rise, then after a few minutes it should drop again slightly as the thermostat opens, then steadily rising again until it stays sat about midway. If sat in traffic for any length of time the temp will rise slightly, but as long as your fans are working and you've no leaks etc it shouldn't rise any more than about 3/4 way up the gauge (about 90 if memory serves correct, maybe slightly higher). But if the gauge continues to rise, you're overheating!
(Don't worry, this shouldn't happen!
) Check all your cooling hoses are in good condition and not perished, split or leaking anywhere. Particularly check the less obvious tucked away hoses. There are a couple of small coolant hoses tucked away down the right hand side of the engine, near the bottom, above the starter motor, leading to the oil cooler plate the oil filter is screwed onto. These have leaked on me in the past. Also check the hoses either side of the radiator at the front of the car and check the radiator is in good condition.
If I sound obsessed with leaks, I am! When I first bought my GTA and started using it regularly, it hadn't been run much previously and as soon as I started using it daily, I think a lot of the hoses where quite perished and brittle with age and lack of use. I ended up replacing every hose as each one sprung a leak! One I didn't catch, hidden away at the back of the water pump in the 'v' of the engine, under the inlet manifold, leaked unnoticed and caused an overheating session which led to blown head gaskets.
But don't be put off!
If your car's been used regularly and maintained it should be fine. Just something to be aware of and check.
Also, check all your fuel pipes are good and not leaking. Fuel pipes leaking onto a hot engine have been the downfall of more than one or two GTAs!
I think most GTA owners also carry around a small toolkit. Just a good assortment of spanners, small socket set, allen key set and some torx headed screwdrivers are sometimes useful. Spare fuses and maybe some spare jubilee clips, small hoses etc. Or a mobile phone and recovery membership!