I have a 99 with a 2.7 engine. I am thinking of changing the belts and hoses. Also, getting a coolant flush and refill. What else should be done for preventive maintenance at this kind of mileage? I have maintained oil changes but thats about it!
I change my oil every 5000 k's. I know at around 100-120 K's you should think about having the timing belt and water pump done.
Other things to look at are transmission flush, change spark plugs and fuel injectors.
The 2.7 has a timing chain, not a belt. My 99 2.7 has 105K miles and all I've done is synthetic oil change every 5k miles with the filter, trans flush every 30 to 40k miles, antifreeze flush and fill around 60k and spark plugs every 50k. It probably would not hurt to have the fuel injectors cleaned but if its running smooth you are probably better off leaving it alone.
As for timing chain and water pump, there are various opinions as to when they should be changed. If you have maintained the car (regular oil changes are the key here) and don't hear any funny noises from the front of the engine (like timing chain rattle) you can let it go for quite a while. If you are worried about the water pump leaking which will cause major problems if it goes for very long, send your oil out for analysis to Blackstone Labs (www.blackstone-labs.com) for $20 which will tell you if there is any indications of water or antifreeze in the oil which would be an early indication of water pump failure. Also watch for drips on the ground around the front of the engine which is another indicator of pump failure. If you are really concerned, then you could have the pump and timing chain replaced now (about $600+ depending on the shop) - also have them replace the chain tensioner and chain guides which a good shop will suggest anyway.
Other than that - treat it nice and enjoy the ride.
If you're not replacing the water pump at a minimum you should check the oil for anit-freeze and you should continue to do it at least once a year from here on out. The water pump will eventually fail and you may not know it 'til it's too late. On the 2.7L that often means degraded oil followed by engine lock-up
I also changed the O2 sensors on our van when we did the 100k check-up. Like the spark plugs the O2 sensors slowly degrade over time and you'll loose engine efficiency. Our van MPG went from 22 new to 18 over seven years and now back to 21 after the 100k mile check-up. But there were only 2 sensors on the van, the 2.7L has four of them - not cheap. You might want to save that change for another time ...