Hi Mate why do you need a smaller reel?
The smaller the reel the smaller the spool is, and the less affective it will be at float trotting. Better is bigger for trotting with a closed face reel something like the ABU 507 or Ryobi techno match, mastermatch
If you really want smaller the abu diplomat is the smallest closed face reel or you could go for a abu 501 or a 506 which would be slightly smaller than your 706
The best closed face reel IMO was the Ryobi by a long way.
Closed face reels are a bit like Marmite or Centrepin reels; you either love them or hate them.
Personally, I've used Abu 500 series reels for a very long time and never had any problems with them at all.
So, I'd opt for the 501 or the 506 myself to go with the lighter 12' rod.
The reason for a small light reel is that the map blank is very light and the 706 is a bit heavy for it. I am not sure spool size makes a huge difference on a closed face as the line comes off the bell which is wider than a fixed spool spool.
How does the ryobi compare weight wise to a 706? I am tempted to try one as many people say they are better than the abu.
The reason for the bigger spool is you get less bedding in.The 706 is a very light reel lighter than the original 500 series. The advantage of the 501 and 506 is they are bomb proof.
The only lighter smaller reel is the abu diplomat lighter than any of the above, but the spool is very small you you do get more bedding in problems.
The Ryobi is about the same weight as a 706 just bigger same size spool as the 507 there is a couple on ebay have a look mate.