Did you ever call Tull Bearing like I suggested in my very first response a week or two ago?. You're not bugging people. Quoting prices is what they do all day as part of their job. Just know what you want. Give them the numbers and leave it at that.
BTW - I thought the differences would be minimal. Still think you're going to have trouble finding that heavy pre-load. I wouldn't worry about it if you can't.
Dave