Re: mechanical or electrical?
No worries mate.
what car is it going on?
If its a xa xb xc i would reccomend using the EL or AU fans and shroud and same size radiator so you can mount it all as one unit. Looks very neat and also works well as they are designed to work together. Only mods required are to move the radiator mounts out wider.
Also re wiring, Wire the fans up together as on the EL or AU but then have a circuit breaker on each one so if one shits itself the other will keep going. Also a manual override switch is good incase the thermo switch dies or if its a hot day and you want them on longer.