I'm a little late to the party but Blip mentioned the Infinity support bots and I'll throw in my support for that idea. I'm seriously considering the idea myself.
I happened to already have a pair of Yu-jing remotes from an early attempt to play infinity a few years back. As far as size goes, the smaller ones are about the same footprint as a FW Warhound. A bit lower to the ground, but the extra length and extra legs give them roughly the same bulk. The larger ones are definitely creeping up into FW Reaver territory.
Here are some super crappy phone cam pics showing some FW titans against a Yaokong (one of the smaller of the remotes). No weapons or heads mounted, just basic frame and legs for rough comparison.
Overall, I think the Yu-Jing aesthetic matches the Marhaf best.
Yaokong These will probably be my basic scout titans if I go this route.
Su-Jian Also scout titans. Not sure what I'll do with the fact that they're apparently transformers, but that alone is too cool to resist.
Yaoxie These will probably be my smaller battle titans.
Haqqislam's aesthetic is a little more bulby than the Marhaf, but has a few of interest:
Kameel are at least Reaver sized and might be large enough for a solid battle titan equivalent to a Warlord. I especially like the EVO version, which would make a great EW/C3 node for an AI-controlled faction. I'd probably replace the soldier packs on the rear with some sort of missile racks.
Shaibs are small, probably more knight than titan sized, but would make good scouting vehicles.
Maghariba Guard are huge. These are easily Imperator size. I believe they're supposed to go on a 4 inch/8cm round base.
Nomads have two that catch my eye:
Lizard seems about the right size for a Warlord titan. I'd probably cut the pilot arms off and replace them with extra weapons from the bits box, though. It's one of the few TAGs in Infinity that isn't toting a giant sword or rifle of some sort, which is a plus for me, as those are scale cues that would make other TAGs look weird in a 6mm army.
Zonds of all sorts have roughly the right aesthetic, but the basic Zond Remotes here have the neat feature of 'roller' wheels, which I think fits the Marhaf style pretty well.
Finally, Aleph has
Rebots, which also have a very solid Marhaf aesthetic, but I'm not super fond of the scorpion tail weapons. However, they've got a very Stalk Tank sort of vibe, and I could see loading them up with some close range anti-infantry weapons for an urban ambush knight/titan.
