Centrifugal Disc and Polishing

I need to improve results on the mass finish process in 14k rings
which mass finish is the best, the fastest, and the economical
choice? how long takes the polishing process?

	-centrifugal barrel(hammond)
	-centrifugal disc(otec,triptonus,,,,,)
	-barrel (Mario Di Maio barrels)

wet or dry??

Usually I polish about 600gms 14k rings 2 times a day(4 people small
shop) in vibratory tumbler and rubber barrel I have seen small
centrifugal disc like OTEC ( www.otecusa.com or BIG like Triptonus
www.triptonus.com and Hammond Roto-centrifugal barrel(very big and
expensive maybe) www.roto-finish.com/

which one should I buy? I thinking in the future(1kg twice a day)
4500usd in a big centrifugal disc? 800usd in a very small (150
gms)OTEC WET centrifugal finisher?, 2000usd in a MariodiMaio barrel?
I use 4 step media process(1-Green plastic media,2-Brown
plastic,3-white media,4-steel media)

Sorry for my english!

Any help appreciated.

mexican jeweller