What kettlebells should I start off with.

[BifWebster]

I am a member of a gym. I also have a bench press, an olympic bar and 300 lbs of weights in my garage. A local store will buy them for 10 cents a pound; or I can get 20 cents a pound store credit. The store has kettlebells and I am somewhat interested in trying some conditioning workout on my off days at home with kettlebells. I am fairly strong (330 bp, 540 dl, 450 sq). But I will be using these more as conditioning tools. I can probably buy at least two with the money I will be getting. I was wondering what the best weighted kettebells would be to start off with; having no experience with kbs.