hey guys so I will be doing a pro audio build but nothing too serious... (2) 6.5" beymas (2) 8" beymas and (2) 4" O2 tweets

If going with an aftermarket HU i would use the pioneer AVH4200DVD.
If going with a processor it would either be the Rockford 3Sixty.2 or the JBL MS-8

My question is what would be the best unit for this type of setup.

 

Both.

 

It's gonna take a whole lot of processing to get those pos speakers to sound even remotely decent

If you're gonna do pro audio, please do it right.