Basic 4-way DiSEqC switches:
- can be very cheap (but DO NOT buy anything branded "BEST" on Amazon - i had a lot of problems with those!) - although those from EMP-Centauri are probably some of the best but more expensive (and sometimes difficult to find - at least in the UK).
- are easy to install - 1 extra short length of sat cable and 2 extra F plugs for each LNB - but it's a good idea to locate the switch where there is some protection from rain etc.., and that might mean that the extra cables are quite long.
- are easy to set up in the receiver - just go into the menus and look for the DiSEqc settings and turn on DiSEqC 1.0, then select ports A-D or 1-4 for each LNB as appropriate.
You can also get 8-1 & 10-1 way switches (but I wouldn't recommend the latter) - and then there's switches like the 16-1 EMP-Centauri down at the bottom of my garden!
That's really all there is (or should be) to do!
As for signal loss, that's marginal at around 1-2 dB per LNB