If you’re planning to to represent mid-5th century Franks (circa Catalunian Fields), it’s probably worth considering that the Franks had been operating militarily within the empire for over a century, much of that time in contact with the Goths, Burgundians and other groups — so I don’t really know how distinct the Franks would have been from the Romans or other ‘barbarian’ peoples in terms of weapons and armour. Angons and franciscae are characteristic weapons for the Franks (I think GB have them available separately), although I get the sense they were used by almost everybody in the mid 5th century.
Sidonius Apollinarus described the appearance of the Franks (funny haircuts, moustaches, tight pants? I can’t remember what else). I don’t know how much of that was describing reality and how much was for literary effect, but it’s something to work from.
Most of the specifically Frankish ranges out there seem to have helmets based on 6th century finds and it’s plausible they were in use earlier. A lot of 28mm Franks have fur or leather vests — not sure where that comes from (probably a WRG/Osprey illustration and/or the Foundry figures).
I don’t know if this has cleared anything up or muddied the waters further. Basically use any of the figures mentioned earlier in the thread. I also don’t think you’d be out of line using figures labeled Goths or even Late Romans for your Franks.