the easiest IMHO is to use slide film and a daylab. Then you can use a variety of size films to create the lift, from 669 film , 59 or 809.
Using 59 would mean haviang a film holder and 4x5 camera. However, for street work, you may find something smaller faster.
You need not limit yourself to 35mm slide film as there is a daylab head that will accept 120 film so a nice folder that uses that size film would be helpful
Daylab also has several other peices of equipment that will allow you to copy prints to the proper film for doing lifts, so you may want to check their website for specific information. (i don't work for them , so i have no dog in this thread)