With a 50K bank, I would suggest playing the 30-300 table, spreading 2x30 to 2x300. This assumes that the minimum doesn�t go up when you play two spots.
One thing that you didn�t comment on is the Heat factor. Are there problems associated with large bet spreads? In some jurisdictions, you can make wide spreads without trouble. If so, you can look at pulling a spot in negative counts.
Now if you spread from 2x30 to 2x300, then, it looks like a 20-1 spread. But it is not as strong as a straight 20-1 spread, because there is a negative card-eating effect. If you get a lot more heat for a wide spread, then it probably isn�t worth it.
Even in your conditions, you should try to get out of some negative shoes. For one thing, when are getting ready to end your session, try to end in by leaving during a negative. Second, see if you can get a occasional courtesy shuffle.
Finally, you might see if you can play at more crowded times. There must be some other players at this casino at some time. If you could have other players at the table, then you can wong out and let them finish the negative shoes.