What kind of ddr3 memory can I put in Vostro 230 and OptiPlex 790 and 380 Desktops?

I have several OEM memory questions.

The first is whether it voids my warranty if I put in memory I don't buy from IBM.

Then I would like to know if it could create problems putting 1.65V 1600MHz and 2000 MHz memory in the following computers.  The original memory was 1.5V.

 Thanks,

Al

 Dell Computers and original specs:

Optiplex 790 with an i3-2100 processor. Processor: Intel Core i3-2100 (3.1GHz , 3 MB Cache) 2 GB DDR3 NON-ECC SDRAM 1333MHz (1 DIMMs)

 Optiplex 380 Processor, E5800, 3.2, 2MB, Wolfdale, 65W, R0 Dual In-Line Memory Module, 4G 1333, 512X64, 8, 240, 2RX8

 Vostro 230 Processor, E5500, 2.8, 2MB, Wolfdale, 65W, R0 Dual In-line Memory Module, 1G 1333, 128X64, 8, 240, 1RX8

Memory I bought:

Patriot PGV34G20000ELK Sector 5 2GB x 2 kit.  It runs at 2000MHz 9-11-9-27 1.65v

Kingston HyperX Genesis KHX1600C9D3K4 4GB X 2 kit 1.65V

Avexir AVD3 Long Dimm Single Channel DDR3-1333 2GB