Hi!
About the banner - the zilant dragon was (and is) indeed in the CoA of Kazan (in Volga Bulgaria), but I'm not sure if it was used by all Bulgars at such an early stage (though there's also a theory that a dragon is depicted on the ring of a Danubian Bulgarian tsar from the beginning of the 13th century too). Not much is known in details about the Bulgars in their Pagan period, especially 5th and 6th centuries, but what we know from the responses of Pope Nicholas I to Khan/Kniaz/Tsar Boris I is that the Bulgars used a horse-tail (bunchuk) as a military banner. Another possible banner and very widely used symbol is this one: IYI, which is believed to represent the power of the Sky-God and his representative, the khan. An example is the
horseman here (the flag being possibly inspired by this
ancient graffiti) and also seen on the
Pliska rosette.
Btw, I've read that on Turkic the groups of Kutrigur/Kuturgur translate to "wandering people" (nomads), while Utigur/Uturgur - to "sitting/settled people". So it would be fitting if the Kutrigurs are more nomadic, while the Utigurs are more settled, possibly even with some differences in ethnic composition (which also explains the somewhat different burial rituals).
Btw, here's an old collection of Bulgar personal names that I had found some years ago:
Alzek
Anzi
Apskhih
Asparukh (Isperikh, Ispor)
Bars
Bataul
Batoya
Batulia
Bayan (Bezmer, Batbayan, Boyan)
Boris
Bulger
Buzan
Chepa
Dizeng
Dometa
Dristar
Drong
Dukum
Elemag
Eskhach
Goleda
Gostun
Grigora
Grod
Guar
Houdbaad (Hudbaad, Khudbard)
Iratais
Isbul
Kano
Karan
Kardam
Khinialon (Chinialus)
Kordil
Kormesiy
Kormisosh
Korsis (Okors)
Kotrag
Krum
Kuber
Kubrat (Kurt, Kuvrat, Krovat)
Kutrigur
Magotin
Malamir
Marmais
Mugel
Odolgan
Okhsun (Okhsi)
Omurtag
Onegavon
Organa (Organ, Ornag)
Oshi
Ostro
Pagan
Praksa
Pressian
Rassate
Sabin (Savin)
Sandilch (Sandil)
Sevar
Shilke (female?)
Sigritsis
Silke (female?)
Sinnion (Synion)
Slavnas
Sondoke
Stazis
Tarasiy
Taridin (Tiradin)
Telec
Telerig
Tervel
Toktu
Tsog
Tsul
Tuk
Turdacis
Umor
Uturgur
Vanand
Vardan
Venda
Vetam
Vinekh
Yani
Zabergan
Zenti
Zvinitsis