Well done for getting into MF. I'm sure you won't regret it.
If your'e going to use Velvia you might be better off with a hand held meter anyway (preferably a spot meter). Some people also use the spot meter on another good film camera. (I have dont this with the spot meter on my OM4Ti before).
As for film supplies, try Mathers of Lancashire (highly reccomended) and Discount Films Direct.