Hi Cap'n & welcome to the forum.
I’ve had the same problem mate, so I'll give you my opinions on both the SM & the BA.
If your buying a stock motorcycle
Thing to consider…….BA
Spoke wheels\tube type
More chrome
Silver engine
Pull back bars (wide) 2†risers
Single front brake calliper
No rev counter on tank
Thing to consider…….SM
Alloy wheels\tubeless
Less chrome
Black engine
Drag bars…4†risers
Twin front brake callipers
Rev counter on tank
Remember these……
To change bars……..Very little cost..(Thanks to BA members)
To add more chrome……..Depends
To change wheels………$£ssss
To add a front calliper……...$£ssss
To add a rev counter……..$£ssss
I did a bar conversion myself (SM to BA) with very little cost.
Hope you choose the right one
Oo....Forgot to mention different seats