Compose a printable jpg or pdf file out of 25 single images

Hi everyone,

Since I am not very proficient in image processing outside my regular use of lightroom for RAW development I need your help:
I want to compose a seemless square image consisting of 25 (30x30cm each) individual square pictures. The composed image should measure 150 x 150 cm.

All around the newly composed image I would like a black frame/background to be added to bring the total dimensions up to 180 x 180 cm (possibly a little more or less, depending on some details I still need to confirm with the printing company during the day of Thursday, Sep.9 German time).

From that image I need two printing files to be created:
1 jpg or pdf file for a print on tarp or similar material with 150 dpi/ CMYK (more details please see below).
1 jpg or Tiff file with 300 dpi/RGB to be used later for prints on regular photo paper.

What I will provide:
After consulting the specifications you should tell me which file fomat you will need to make this task as easy as possible for you. I will then provide you with 25 individual image files named in the order that they should be lined up in the composition (e.g. Top row 1 to 5, second row 6 – 10 etc.)
Any further assistance that you may need.

And of course I need the finished work yesterday …
No, seriously, I have no clear idea neither of the time required nor what an adequate amount would be to decently remunerate your work.
The job seems pretty straightforward to me but then again, if I new how to it properly I certainly would do it myself.
So I am putting a number because I have to with my apologies if the amount is ridiculously low.

In your offer please quote he amount that you think will cover your efforts comfortably.
Also please give me a realistic time frame within which you can finish the project.

Thank you very much in advance for your consideration.

Dirk

P.S.: Please note that I am posting this before retiring for the night. So I will not be able to respond for several hours.