Welcome to here; before you purchase, post where you found it--there are some dealers that have burned members, so we tend to steer others away from those places. As far as street bikes go, it seems that Dongfang has it covered--they have the same engine in a few different bikes. I am linking their street bike page, as I know a few are currently offered.
http://www.df-motor.com/Product.asp?...me=Motorcycles Member Barnone has a thread on the model DF250RTG under the 'Street' section. Their bikes are technically 49 state legal.
CSC offers two air-cooled bikes; one is an enduro like the Hawk (which I am sure you are familiar with) called the TT250 and the other is the SG250 which is near-identical to the DF250RTG
https://www.cscmotorcycles.com/ CSC sell directly to the consumer, meaning they assemble/PDI and fill up the bike with fluids including gasoline, so the only thing you do is uncrate it, and register it--their bikes are 50 state certified.
The Hawk is very popular, and is generally the lowest cost, although you will probably have to mod it slightly to get it to where you want it--there are like a million members with it, and all of the assembly, mods, and customizing threads associated with the Hawk are here, not to mention numerous videos on youtube. What it lacks in initial refinement is more than made up by reading the threads. The Hawk is technically certified as an off-road only bike, although numerous states have registered them. Keep in mind that some states that used to plate them are no longer doing so.
Bashan offers the Storm 250, the Brozz 250, the BSR 250 and a street/adventure-ish bike--all but the Brozz are shown here and don't let the mislabeling the bikes as Apollo fool you (the top pit bikes are Apollo--the rest are Bashan...
https://gokartsusa.com/Apollo-70-Pit...e-3-Speed.aspx Bashan reportedly are higher quality bikes overall than other Chinese bikes, and seem to often have slightly higher prices as well. Their BSR 250 is near identical to the Hawk, but is certified for 49 states, so if you like the Hawk, but live where you cannot register one, this bikes would be the next best thing. The page I linked is an actual retailer, although I do not know their reputation. They have been around several years, so that should prove something.
Taotao has just released an enduro bike called the TBR7. A couple members have reported purchasing them, and seem initially pleased with them.
http://taotao.us/index.cfm/electric-vehicles/tbr7/
BMS have also recently released an enduro called the CRP 250; initial happiness with the disclaimer that it has not been around long. However, it's OEM is Bashan (the paperwork states Bashan) so you are getting a known quality bike. BMS is also going through the trouble of getting it CARB certified, so it will be 50 state legal.
https://www.bmsmotor.com/index.php/v...o-250-crp.html
I know I am missing some if not several, so others will chime in.