A/C control unit too big, Replace?

Hi everyone and good morning, I have an old 1982 mercedes benz 300td which has been modified for a gps system. although the system is double din and takes up alot of room, so much so that the OEM A/C unit does not fit. I was wondering if anyone could offer advice on how to cut the units size down, or how to replace it with an aftermarket unit that not only looks appealing and wil l match my gps system but will be compatible with the mercedes A/C system already installed. My understanding is that there arnt aftermarket controlers out there, although I pray this is not the case. Thankyou in advance to anyone that can help me out.

EDIT: Okay, I looked again with new keywords and found China suppliers for aftermarket units, although I have no idea on how to install a unit to make it work with my system.