If your book does not offer it you can make it yourself.
After all, a -1 line is nothing more than a push when your team wins with one. To make your own -1 line you therefore have to make sure the potential profit you make on the ML is the same as the amount you have bet on the RL. If your team wins with one, you will win the ML and lose the RL for a netto-push.
So if you have a -140 line you could bet $140 on the ML and $100 on the RL. If, instead, you want your total bet to be $200 and the ML is -155 then it is a simple equation
(1.55 + 1)x = 200
x = 200/2.55 = 78.43 So you have to bet $78.43 on the RL and 1.55*78.43 = $121.56 on the moneyline.
Of course, this would need a calculator [unless you find/make a program for it] but just in case you do not find a book offering a -1 line.