First off, welcome to 3 Wheeler World!
Next, lets find out what you have. There are a few possibilities from what you described, it could be a.....
1983-1984 YTM 200E: 4 stroke, shaft drive, front suspension, electric start
1985 YTM 200ERN: 4 stroke, shaft drive, front suspension, electric start, reverse
1983-1985 YTM 225DX: 4 stroke, shaft drive, front suspension, electric start, rear suspension
1985-1986 YTM 225DR: 4 stroke, shaft drive, front suspension, electric start, rear suspension, reverse
As for the bearings, I usually order mine from denniskirk.com or you can get them from a member here (username: dads). Maybe someone else will post up the numbers, I don't have them. I have brought them in to a bearing shop before and they matched them up, same with the seals (yes, it’s a good idea to replace the seals as well). All in all it shouldn't be more the $20 for the bearings and seals.
1984 Yamaha YT 60 Tri Zinger(current project)
1983 Yamaha YTM 200 (rear suspension kit)..... long term project
2004 BMW R1150R
1972 Honda CT 70
2007 Lifan 110