If this is the block from Bob Mendez you can sleep easy. He is a very fair dude. I did a post on YellowBullet about this subject about a year ago and got some real good feedback. In a nutshell;
1)Use the 'good' sleeves I think Melling offers 2 different versions and they're priced reasonable.
2)If you decide sleeve all 8, fit the sleeve O.D. to maintain maximum integrity (wall thickness) in the block foundation. If you 'go big' and bore thru the factory casting, the block will be compromised in strength.
3) Choose a shop that's had a good proven track record for this process. I'm not saying there is only one way to do this. On that 'thread' a couple shops that had success in the process had disagreed on the best method.