Each relay can handle 10-25 amps or more if you are careful about what relays you use. You can use several relays if needed. The current draw for a relay coil is less that 1 amp, so there isn't much of a problem with overloading the circuit they get coil power from. Remember that each relay needs a fuse between it and the power feed for the relay contacts.
Aircraft type circuit breakers are designed for low voltage DC applicaions and would be an excellent choice to replace fuse links or fuses. They come as a push/pull to reset button, and range from 1.5 amps to 60 amps and higher.
See
http://www.aircraftspruce.com/index.php or
http://www.wicksaircraft.com/catalogDetails.php or
http://www.sacskyranch.com/ for circuit breakers and other items.
There is a store local to Orlando that does electronic surplus and has all kinds of circuit breakers. That's where I get most of my wiring supplies. There may be a similar type store in your area. See
http://www.skycraftsurplus.com/
Fuse links come with a current rating just like fuses. A clue as to what current they are designed for is to look at the size wire they protect. Here's a table:
18 gauge wire = 5-8 amps
16 gauge wire = 10-12 amps
14 gauge wire = 15-17 amps
12 gauge wire = 20-25 amps
10 gauge wire = 30-40 amps
8 gauge wire = 50-60 amps.
Keep in mind that the wire size in the chart is for the circuit itself, not the size of the fuse link. The packages of fuse link repair material you can get at the auto parts stores also will have a current rating on them.