Pumps

Agilent (cheapest option, has ion pumps, might be worse quality than other suppliers)

Pfeiffer (very responsive, more expensive)

Leybold

Edwards (Gamma Vacuum for ion pumps)

Iwata (roughers)

3rd party:

Ideal Vacuum (https://www.idealvac.com/Vacuum-Pumps/ct/1362)

High Vac Depot (https://highvacdepot.com/)

Flanges and Other Vacuum Equipment

Kurt J. Lesker (https://www.lesker.com/)

NorCal (https://www.n-c.com/) (under Pfeiffer)

Accu-Glass (https://www.accuglassproducts.com/)

MKS (https://www.mks.com/)

Ideal Vacuum (https://www.idealvac.com/)

VAT (https://www.vatvalve.com/?_locale=en&region=US)

UHV Pressure Gauges and Controllers

Inficon (https://www.inficon.com/)

InstruTech (https://www.instrutechinc.com/)

Agilent (https://www.agilent.com/)

MKS (https://www.mks.com/)

Duniway (https://www.duniway.com/)

Vacuum Chamber

Kurt J. Lesker (https://www.lesker.com/)

Atlas (https://www.atlasuhv.com/products/vacuum-chambers/)

Precision Cryo (https://www.precisioncryo.com/)

Ideal Vac (https://www.idealvac.com/)