Vacuum Hold down Recommend Size ? 10 hp / 20 hp or rotary vane

We recently have been working with a company that orders small parts from us. They are are made from MDF and Plywood, We have a 10 hp Regen Vacuum Pump and it has trouble holding the small parts. Sizes range from 12" item to 8" items, they have started to order alot more each time and more frequently. We are looking into upgrading our vacuum system and the dealer has offered us 3 options. We currently use tabs to hold the items but it requires additional sanding to remove the tab and cost us alot of extra work.
Our work area is 4x8 but we only use 4x5 on this job type (Plywood is 5'x5')

1. Two 10 hp Regen Pumps ($1500 - Would only have to buy one)
2. One 20 Hp Regen Pump ($6000)
3. One 12 Hp Becker Vacuum Pump ($8000)

What option would you guys recommend - We are thinking about the 12hp Becker Pump the dealer say this will give us the best hold down but its the highest priced option. I just want to make sure well get a lot more pressure for the 80% price increase.

Thanks for Help
Robert