I have been using the Protostar for it normally. I’ve been looking into the Phenom for it, and suggestions? i would love if some one could tell me a good OD for horizontal.
The One Drop Burnside, Code 2 Nautilus, and Code1.
The three mentioned above are all great choices, the Burnside being my personal favorite of the three. If you would like some undersized horizontal action you might give the Dietz a serious look as well.
Code2 I think would be the best
I had a SPYY Solaris and a Code 1. I found the Solaris was a better horizontal player.
I just finished spending a few weeks with the c3yo Yeah3 which is designed with horizontal play in mind. Did a review here:
http://www.sniffy-yo.com/2012/03/c3yo-design-yeah3-yoyo-review.html
I definitely recommend it. I’m just getting into horizontal play and found it to be very stable while holding its angle.
The toxic hazmat has also been a good one for me to explore horizontal on.
Sniffy-Yo.com
@Sniffyo on twitter
thanks sniffy, that review helped a TON 
im thinking about the YEAH3 now
another throw to add to you plate possibly would be a werrd irony. It’s a bit big at 2.3", but it’s pure performance. Still the best competition throw out there in my eyes.
Dark Sonic and Trident. I have the Trident and it is absolutley wonderful for horizontal.