Train in a -6 or -7
It can be difficult to find a -4 with full dual controls in the rear AND an instructor small enough to fit in the back AND prepared to give you training without a view of the instrument panel.
I took my tailwheel training in a -7 (Mike Seagar). This was very effective, I found the -4 easier to land than the -7.
If you don't find someone to train you in the -4 I recommend this approach.
