Help with transistor substitutions

[cathexis]

Hi!
I'm going to start building a DOD FX75-B flanger from the schematic here:

http://files.muziq.be/schematics/dod_fx75b.gif

There are a few transistors on the schem that I don't have, and I would appreciate any ideas about possible subs before I start hunting them down. I think they're mainly used for switching here. Anything critical?

J113 N-channel FET (could I use a 2SK30A? Or 2N5457?)

MPS4124 NPN

MPS4125 PNP

I'll post a vero layout of this if I get it going.

LARS