I replaced my standard front springs with Hagon progressive springs. I got them online through a company called wemoto. Wemoto Home
They do a load of pattern parts for the XT and are pretty speedy in delivery.
When i took the forks to bits to install the new springs, it has metal spacers installed for the original springs, i cut these in half and used them with the progressive springs. The reason i did that is ive got a 40 litre tank and wanted to make sure they could take the extra weight, when i decide to fill it up to the brim.
They were a real biatch to get in but seem to work fine.
On the rear, i used the standard spring on my last big trip, 12000 ks through West Africa to Ghana, me and a load of luggage, spare tyres water etc. Never had any problems or faults with it.
May look at putting a better spring on the standard shock as ive put on a few pounds since then.