line chart recommends (for Echo 5122-4) - Skagit heads 300 to 350 grains
[given as total grains of head/length of head/grains per foot]
Original Skagit: (may be n/a) 350 / 27' / 13
Airflo Rage: 360 / 28' / 12.9
Skagit Compact: 360 / 23' / 15.6
Skagit Max Short: 350 / 20' / 17.5
OPST Commando: 275 / 13.5' / 20.4
Skagit Trout Max: 275 / 11' / 25
the grains/foot of the head determines what grains/foot of tip you can cast, so choice of head determines what tip(s) you may huck
eg T11 = 11 grains/foot, T14 = 14 grains/foot etc...
Running line: for these lighter short heads, 25 - 30lb mono will do fine.
Leader: the length & diameter is determined by the size/weight/bulk of fly you will be casting:
Backing: whatever your personal choice is, but 30lb standard or 20lb if you're targeting fish that are either @ the smaller end of the scale, or aren't likely to take runs of >150 yards
Reel: large enough spool to accommodate the above selections, plus however flexible your budget is.