Which tires for my 20's?

[clemsonteg]

I have a set of 20" Torq thrust st (5.5" bs) going on my 70 c10. I have a stage 1 front and rear bag kit ready to go on this winter. I have future plans to do a drop spindle in the front, but that will be in a year or two. I'm looking to buy tires for my rims and I'm looking at either a 255/40 (28") or 245/45 (28.6"). Are either of those too tall? Bags are really for a nice ride and to air out when parked. Any other suggestions for tires?