Fenders and rear rack, 29 X 2.30

[Skelshy]

Tires on the new ride are Continental Cross King, 58 - 622 aka 29 X 2.30

SKS has two sets of fenders ... do I need to worry about having both fenders and rack in the rear? Any other brands I should consider?

Are there racks which have a spring-loaded thingy and a rail ? Has a standard emerged for these click-on rails?

Thanks!