If you take your Defender villain side for the Villain epic pools you can pick up a S/L +Def shield from....Mako? Black Scorpion? One of them anyways.
With that you can soft-cap S/L pretty easily and get some decent values for the positions (30's-ish) from Weave, Manuevers and set bonuses.
"Striving for the impossible" doesn't mean "toiling in vain". It means growth. It means improvement in the direction of your ideals. Not futility.
Erfworld: the Battle for Gobwin Knob
You can hit the S/L Def Cap pretty easily by taking Mace Mastery. I think I hit it using the following:
Mace Mastery DEF Shield (2x Def IO and a LOTG)
Weave (LOTG and 1x Def IO)
Manuevers (LOTG)
Hover/Combat Jumping (LOTG)
Tough (Slotted with Steadfast Protection)
Boxing (Slotted with Kinetic Combat)
This also leaves the rest of my defenses at around 20%. If you focused more on DEF sets I'm sure you could raise the rest.
Just roll a bubbler. 
Here's a quick first run for Emp/Elect, lots could be improved, but you'd be very well defended from Ranged, S/L/E (most melee), and fairly well defended from AoE.
Hero Plan by Mids' Hero Designer 1.92
http://www.cohplanner.com/
Click this DataLink to open the build!
Level 50 Mutation Defender
Primary Power Set: Empathy
Secondary Power Set: Electrical Blast
Power Pool: Speed
Power Pool: Leadership
Power Pool: Flight
Power Pool: Fighting
Ancillary Pool: Mace Mastery
Hero Profile:
Level 1: Healing Aura -- Heal/EndRdx(A), EndRdx/Rchg(5), Heal/Rchg(7), Heal/EndRdx/Rchg(7), Heal(9), Regen/Rcvry+(9)
Level 1: Charged Bolts -- Acc/Dmg(A), Dmg/EndRdx(5), Dmg/Rchg(11), Acc/Dmg/Rchg(11), Acc/Dmg/EndRdx(13), Dmg/EndRdx/Rchg(13)
Level 2: Heal Other -- Heal/EndRdx/Rchg(A), Heal/EndRdx/Rchg(3), Heal/EndRdx(43), Heal/Rchg(45)
Level 4: Lightning Bolt -- Acc/Dmg(A), Dmg/EndRdx(15), Dmg/Rchg(15), Acc/Dmg/Rchg(17), Acc/Dmg/EndRdx(17), Dmg/EndRdx/Rchg(19)
Level 6: Ball Lightning -- Acc/Dmg(A), Dmg/EndRdx(19), Dmg/Rchg(25), Acc/Dmg/EndRdx(25), Dmg/EndRdx/Rng(27), Dam%(27)
Level 8: Clear Mind -- EndRdx-I(A)
Level 10: Hasten -- RechRdx-I(A), RechRdx-I(29)
Level 12: Fortitude -- HO:Membr(A), HO:Enzym(29)
Level 14: Maneuvers -- HO:Enzym(A), HO:Enzym(31)
Level 16: Aim -- RechRdx-I(A), RechRdx-I(42)
Level 18: Recovery Aura -- EndMod/Rchg(A), EndMod/Rchg(31), EndMod-I(33), RechRdx-I(33)
Level 20: Hover -- HO:Enzym(A), HO:Enzym(21), Travel(21), Travel/EndRdx(23), ResKB(23)
Level 22: Boxing -- Empty(A)
Level 24: Tough -- ResDam/Def+(A), 3defTpProc(45)
Level 26: Regeneration Aura -- Heal/Rchg(A), Heal/Rchg(33), Heal/EndRdx/Rchg(34), Heal/EndRdx/Rchg(34)
Level 28: Tesla Cage -- Acc/Hold(A), Acc/Rchg(34), Rchg/Hold(36), EndRdx/Rchg/Hold(36), Acc/EndRdx/Rchg/Hold(36), %Hold(37)
Level 30: Weave -- HO:Enzym(A), HO:Enzym(31)
Level 32: Adrenalin Boost -- EndMod/Rchg(A), EndMod/Rchg(37), Heal/EndRdx/Rchg(37), Heal/EndRdx/Rchg(39)
Level 35: Voltaic Sentinel -- Acc/Dmg(A), Dmg/EndRdx(39), Acc/EndRdx(39), Acc/Dmg/EndRdx(40), Acc(40), Dmg(40)
Level 38: Tactics -- ToHit(A), ToHit/Rchg(42), ToHit/Rchg/EndRdx(42), Rchg/EndRdx(43), ToHit/EndRdx(43), Build%(50)
Level 41: Scorpion Shield -- HO:Enzym(A), HO:Enzym(46)
Level 44: Web Cocoon -- Acc/Hold(A), %Hold(45), Acc/Rchg(46), Rchg/Hold(46), EndRdx/Rchg/Hold(48), Acc/EndRdx/Rchg/Hold(48)
Level 47: Summon Disruptor -- Acc/Dmg/Rchg(A), Dmg/EndRdx(48), Dmg/Rchg(50), Acc/Rchg(50)
Level 49: Vengeance -- HO:Membr(A)
Level 50: Spiritual Radial Boost
------------
Level 1: Brawl -- Empty(A)
Level 1: Sprint -- Empty(A)
Level 1: Vigilance
Level 2: Rest -- Empty(A)
Level 4: Ninja Run
Level 2: Swift -- Empty(A)
Level 2: Health -- Rcvry+(A)
Level 2: Hurdle -- Empty(A)
Level 2: Stamina -- EndMod-I(A), EndMod-I(3)
Or just roll a Trapper, see build in sig.
I have been thinking of dusting off my original character from release which was an emp/elec defender and starting playing around with mids some to see what I could do with him. I had some problems getting defense up very high and was wondering if anyone else had similar issues.
I was able to squeeze out about a 35% to AE and only a 21 to 29% to ranged. S/L I could only get around 16% or so but S/L resistances were no problem (usually over 50%)
So.. I started working on effect resistances instead figuring that I had heals anyway so it should not be as much of an issue. I just thought I would ask is what most others found to be the case?