Question about Sigils

When I first started playing Rift, I made a general all purpose sigil with a bunch of different essences in it that I picked up from drops (not every good ones).  Then I made a water sigil for HK which gives me 490 water resist with essences that took me months to acquire.  Now I'm wondering if I have to start making yet another sigil for ID (a fire resist one, I've heard) or whatever else is coming with SL.  I mean really, how many sigils does one need?  Any advice is appreciated.

ID Needs both Earth, and Fire. You can pretty much count on needing a sigil for each of the elements in the game. The good news is, you really only need ~300-350 ISS (+20k Planarite) to make a decent resist sigil, add 60 ISS and 30k Planarite for the runes you can apply to the sigil if you want that added resist.. Purchase the lessers from the vendors and do Raid Rifts of the matching resist you need to get the dropped lessers to finish off the sigil.