You should be able to get a compact for this bike, but as well as the crankset, you will probably also need to change the bottom bracket. Hopefully your current BB will come out without a struggle, but there can occasionally be problems with getting ones out of 10-year old bikes that have never been removed before.
There shouldn't be any need to change your front derailleur. At least, try it with your current one and only consider changing it if you are not happy with how it performs.
One more thing to consider, modern cranksets are made for 9, 10, or 11 speed chains, so the chainrings are slightly closer together. You'll still be able to use your 8-speed chain, but it may rub on the large ring when on the small ring and you use the smaller cogs in the back. You could avoid this by using a 10-speed chain (while still using the 8-speed cassette and derailleurs).