The removal of duplicate files

I will order simple project: the removal of duplicate files, about 217 thousand files (small size) , all packed 2,5 gb.

The files are in the format:

Guitar Pro5 - .gp5 and maybe (space .gp5)
Guitar Pro6 - .gpx
GP3 - .gp3
GP4 - .gp4
PTB - .ptb
Guitar Pro document - .gp

at the beginning: (screen shot)

.ptb files have word (power) in the name and that extra word (power) with parentheses and numbers must be removed::
for example.:

+44 - Cliff Diving (Power) - 437621.ptb na> +44 - Cliff Diving.ptb

so that all the files have the same name (they will different in weight kb, extension and numbers in names) you probably need to remove the numbers from them:
for example.: ,,- 437621" and then delete the files according to the guidelines.

I want only .gp5 files from the duplicate files.

example, if there are 6 duplicate files with the same names (different numbers) , I want only .gp5 ---- (.gp4),(.gp3),(space .gp5),(ptb),(.gpx),(.gp) must be removed.

so there should be only 1 file with the same name (.gp5) (if there are 6 duplicate files with only .gp5 ---- there should be only 1 file about the largest size kb.

if there is only one file in the following format: (no duplicate names (numbers from files previously deleted) of other files) I want it to be and not to be removed.

Guitar Pro5 - .gp5 and maybe (space .gp5)
Guitar Pro6 - .gpx
GP3 - .gp3
GP4 - .gp4
PTB - .ptb
Guitar Pro document - .gp

(maybe software help: bulk rename utility) / (or maybe you have a different solution)