Each of the series have their good points, attraction for a western audience, (even Hibiki-think Inuyasha, Naruto, Samurai/Ninja films) and drawbacks.
I'm however thinking they'll go for Faiz for a number of reasons, not in any particular order:
A. The designs are very different from Dragon Knight/Ryuki, while still maintaining basic identifiable traits (such as large visors, heavy use of bikes, multiple finishers, red and black main riders). By using a contrasting design (Mechanical rather than Tech/Alien/Magic) it allows the show to represent that it will vary in nature to the audience instead of re-using elements/gimmicks to often (such as immeadiately going for Blade after Dragon Knight).
B. Each character has a large arsenal and attack types like Dragon Knight/Ryuki and the Advent Cards.
C. They NEED to use Faiz soon because if they wait any longer the well-disguised, high tech Rider Phones (and related weaponry) will look old-hat and out of date. It would be like using early 90s Computer-based devices, in the early 2000s, and probably wouldn't go over well with the young audience, who would probably regard the big bulky flip phones as "ancient."
D. Tron sequel is coming out, Faiz had Tron-ish designs and it could become a new "it" thing again in sci-fi soon.
E. Modest size of Riders (about five main ones, not including the RioTroopers, or the live show Riders (Alpha, Beta, Gamma)) Relying on too many large cast Rider shows too quickly might cause problems when we enter smaller cast show groups (such as Agito/Kuuga). Five is the average number and would be good to slowly reach equlibrium.
F. Multi-use Rider belts, seems to not be a foreign idea for the creators, so that might not be a problem.
G. Pre-made bikes that already come with transforming gimmicks, as well as an option, or not, to make new bike designs for Psyga/Orga/Delta for "NEW" toys. And multiple weapon toys per Rider each with slightly different gimmicks and designs. Not something to pass up.
H. The footage wouldn't look too out of place, and still look "improved" as it is one year after Ryuki. Jumping around the production chronology would just look weird as time goes on.
I. Instant open options for "villain" and "hero" riders with the same suits, with even more options with new "Henshin" protagonists/antagonists (i.e. the Orpenoch's). This also allows for a mysterious and yet heroic introduction to Kaizo-Ningen based characters without veering directly into Biological riders or having it come completely out of nowhere and it makes a good story element too. ("He who fight monster's" sort of thing)
It could go any way though.
