Hi SA: Since you arnt getting many answers to your question perhaps this will help. I have 5 float rods some are Custom built some are home built. 2 are 10'6 for special puroses like smaller streams and lighter rods;the others are 11'or 12' rods.
For alround use I would suggest 11 to 13' as ideal .This length allows you to hold all the line in the air even on longer casts and drifts.
In my experience the best of the float rod blanks come from Sage,Talon or Loomis. Unfortunatly Loomis seems to be moving away from float rods offering only a few ,Talon has the greatest variety and while Sage are beautiful rods they tend to be prone to breakage,although I havent broken any of mine;( X crossed fingers)
If you plan to fish a centerpin I would strongly recommend maximum length rods,if you fish a baitcaster reel then 11 feet is probably the best length.