Shift registers, and switching pos vs neg side.

[Barnys1]

Hi
I have been considering using an Audrino, Pi etc to switch a few relays and had settled on a shift register (e.g. 74HC595) coupled to a ULN2803 which (as I understand it) controls the relay by switching the neg side of the relays coil.

However, I have access to some (cheap) 5V, 403mW, 2 coil latching relays (RT424F05) which have the coils sharing a common ground.   http://www.alliedelec.com/m/d/ac6e4de0241f77689527aa59e6c4b307.pdf

I have fond countless examples of people achieving shift register switching by controlling the neg side of the “to be switched“ components, but I have found surprisingly little on shift register being used to switch a circuits pos side. 
Is there something similar to the ULN2803 that I could use to switch the pos side of the relay coils? 

Also, in my limited understanding, I thought that all things being equal, it is better to place a switch on the positive side of a circuit, is this correct?

Regards.

[matseng]

According to the datasheet the 2-coil version have the A3-terminal as a shared power, not a shared ground. So you should be able to continue using the ULN28xx.

[Ian.M]

If you really need a high-side equivalent to the ULN2803, look at the MIC2981.

[David Hess]

Low side switching has the advantage of easily using NPN bipolar or n-channel MOSFETs which are more economical than their PNP and P-channel counterparts.