Digidurst,
Congrats! The Mamiya C330f is the best of the bunch (IMO). I reckon a Gossen Profisix would suit you admirably. They're not made anymore so I reckon you should be able to get one fairly cheap. They are extremely reliable, durable and easy to use (a bit like your Mamiya). I've been using a profisix for 20 years and it's seen a lot of action. You can buy lots of different attachments to turn it into spotmeter, flashmeter, colour temp. meter etc. It has an incident metering diffuser built-in and if that wasn't enough, the later models incorporate a zone system numeral scale, should you wish to go down that road. Regards, BLIGHTY