What DDR3 memory can I use in my Dell Optiplex and Vostro Desktops?

I want to know if there would be any problem putting the following memory into the following Dell computers.  I understand that the Averxir is single channel, so there’d be some loss of efficiency there.  And also it could void my warranty on the Dell computers if something happened.  My concern is whether the Patriot and Kingston Kits might create real problems if I put them in the following computers, since they run at 1.65V and at 1600 and 2000MHz.  Is it like the bad old days where the wrong memory could even fry your motherboard?

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