CHEERS for the advice
Any recommendations as to how many SAE I would need to keep my tank looking spiffy

or just start out with 5-6 and add more in the future if they are not doing a good enough job?
5-6 will do far better than a good enough job as far as keeping algae down.
I recently had to move 2 to my 75 gallon tank on account of having to get rid of their old tank.My 75 gallon had lots of black hair algae covering all the rocks and top sides of the wood.They ate ALL of it with-in 2 weeks,and they keep it trimmed down so's you can't even tell there is any in the tank at all.