U can buy yourself some bar-end brakes, if you're totally new to bullhorns, it will be smart to first purchase a bar --> check the inner diameter --> buy yourself some brakes. Bar-end brakecables always go through the handlebar. So if there aren't any holes, you will have to drill them. It is not that hard :)
Don't do this on Aluminuim bars, it's an accident waiting to happen.
I'd advise against Cinelli Lola, as they're not drilled for internal brake cable routing (which you'll need for tt style brake levers). Much better is the Deda Crononero, comes in a range of styles and widths and is drilled for brake cables. Hopefully a bit easier for you to find too ?
@Ste_S
Don't do this on Aluminuim bars, it's an accident waiting to happen.
I'd advise against Cinelli Lola, as they're not drilled for internal brake cable routing (which you'll need for tt style brake levers). Much better is the Deda Crononero, comes in a range of styles and widths and is drilled for brake cables. Hopefully a bit easier for you to find too ?